Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
News for the tz database

Release 2020d - 2020-10-21 11:24:13 -0700

  Briefly:
    Palestine ends DST earlier than predicted, on 2020-10-24.

  Changes to past and future timestamps

    Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
    as previously predicted (thanks to Sharef Mustafa.)  Its
    2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
    Thorsen.)  Its 2015-10-23 transition was at 01:00 not 00:00, and
    its spring 2020 transition was on March 28 at 00:00, not March 27
    (thanks to Pierre Cashon.)  This affects Asia/Gaza and
    Asia/Hebron.  Assume future spring and fall transitions will be on
    the Saturday preceding the last Sunday of March and October,
    respectively.


Release 2020c - 2020-10-16 11:15:53 -0700

  Briefly:
    Fiji starts DST later than usual, on 2020-12-20.

  Changes to future timestamps

    Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
    previously predicted.  DST will still end on 2021-01-17.
    (Thanks to Raymond Kumar and Alan Mintz.)  Assume for now that
    the later-than-usual start date is a one-time departure from the
    recent pattern.

  Changes to build procedure

    Rearguard tarballs now contain an empty file pacificnew.
    Some older downstream software expects this file to exist.
    (Problem reported by Mike Cullinan.)


Release 2020b - 2020-10-06 18:35:04 -0700

  Briefly:
    Revised predictions for Morocco's changes starting in 2023.
    Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
    Macquarie Island has stayed in sync with Tasmania since 2011.
    Casey, Antarctica is at +08 in winter and +11 in summer.
    zic no longer supports -y, nor the TYPE field of Rules.

  Changes to future timestamps

    Morocco's spring-forward after Ramadan is now predicted to occur
    no sooner than two days after Ramadan, instead of one day.
    (Thanks to Milamber.)  The first altered prediction is for 2023,
    now predicted to spring-forward on April 30 instead of April 23.

  Changes to past and future timestamps

   Casey Station, Antarctica has been using +08 in winter and +11 in
   summer since 2018.  The most recent transition from +08 to +11 was
   2020-10-04 00:01.  Also, Macquarie Island has been staying in
   sync with Tasmania since 2011.  (Thanks to Steffen Thorsen.)

  Changes to past and future time zone abbreviations and DST flags

    Canada's Yukon, represented by America/Whitehorse and
    America/Dawson, changes its time zone rules from -08/-07 to
    permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
    This change affects only the time zone abbreviation (MST vs PDT)
    and daylight saving flag for the period between the two dates.
    (Thanks to Andrew G. Smith.)

  Changes to past timestamps

    Correct several transitions for Hungary for 1918/1983.
    For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
    (Thanks to Géza Nyáry.)  Also, the 1890 transition to standard
    time was on 11-01, not 10-01 (thanks to Michael Deckers).

    The 1891 French transition was on March 16, not March 15.  The
    1911-03-11 French transition was at midnight, not a minute later.
    Monaco's transitions were on 1892-06-01 and 1911-03-29, not
    1891-03-15 and 1911-03-11.  (Thanks to Michael Deckers.)

  Changes to code

    Support for zic's long-obsolete '-y YEARISTYPE' option has been
    removed and, with it, so has support for the TYPE field in Rule
    lines, which is now reserved for compatibility with earlier zic.
    These features were previously deprecated in release 2015f.
    (Thanks to Tim Parenti.)

    zic now defaults to '-b slim' instead of to '-b fat'.

    zic's new '-l -' and '-p -' options uninstall any existing
    localtime and posixrules files, respectively.

    The undocumented and ineffective tzsetwall function has been
    removed.

  Changes to build procedure

    The Makefile now defaults POSIXRULES to '-', so the posixrules
    feature (obsolete as of 2019b) is no longer installed by default.

  Changes to documentation and commentary

    The long-obsolete files pacificnew, systemv, and yearistype.sh have
    been removed from the distribution.  (Thanks to Tim Parenti.)


Release 2020a - 2020-04-23 16:03:47 -0700

  Briefly:
    Morocco springs forward on 2020-05-31, not 2020-05-24.
    Canada's Yukon advanced to -07 year-round on 2020-03-08.
    America/Nuuk renamed from America/Godthab.
    zic now supports expiration dates for leap second lists.

  Changes to future timestamps

    Morocco's second spring-forward transition in 2020 will be May 31,
    not May 24 as predicted earlier.  (Thanks to Semlali Naoufal.)
    Adjust future-year predictions to use the first Sunday after the
    day after Ramadan, not the first Sunday after Ramadan.

    Canada's Yukon, represented by America/Whitehorse and
    America/Dawson, advanced to -07 year-round, beginning with its
    spring-forward transition on 2020-03-08, and will not fall back on
    2020-11-01.  Although a government press release calls this
    "permanent Pacific Daylight Saving Time", we prefer MST for
    consistency with nearby Dawson Creek, Creston, and Fort Nelson.
    (Thanks to Tim Parenti.)

  Changes to past timestamps

    Shanghai observed DST in 1919.  (Thanks to Phake Nick.)

  Changes to timezone identifiers

    To reflect current usage in English better, America/Godthab has
    been renamed to America/Nuuk.  A backwards-compatibility link
    remains for the old name.

  Changes to code

    localtime.c no longer mishandles timestamps after the last
    transition in a TZif file with leap seconds and with daylight
    saving time transitions projected into the indefinite future.
    For example, with TZ='America/Los_Angeles' with leap seconds,
    zdump formerly reported a DST transition on 2038-03-14
    from 01:59:32.999... to 02:59:33 instead of the correct transition
    from 01:59:59.999... to 03:00:00.

    zic -L now supports an Expires line in the leapseconds file, and
    truncates the TZif output accordingly.  This propagates leap
    second expiration information into the TZif file, and avoids the
    abovementioned localtime.c bug as well as similar bugs present in
    many client implementations.  If no Expires line is present, zic
    -L instead truncates the TZif output based on the #expires comment
    present in leapseconds files distributed by tzdb 2018f and later;
    however, this usage is obsolescent.  For now, the distributed
    leapseconds file has an Expires line that is commented out, so
    that the file can be fed to older versions of zic which ignore the
    commented-out line.  Future tzdb distributions are planned to
    contain a leapseconds file with an Expires line.

    The configuration macros HAVE_TZNAME and USG_COMPAT should now be
    set to 1 if the system library supports the feature, and 2 if not.
    As before, these macros are nonzero if tzcode should support the
    feature, zero otherwise.

    The configuration macro ALTZONE now has the same values with the
    same meaning as HAVE_TZNAME and USG_COMPAT.

    The code's defense against CRLF in leap-seconds.list is now
    portable to POSIX awk.  (Problem reported by Deborah Goldsmith.)

    Although the undocumented tzsetwall function is not changed in
    this release, it is now deprecated in preparation for removal in
    future releases.  Due to POSIX requirements, tzsetwall has not
    worked for some time.  Any code that uses it should instead use
    tzalloc(NULL) or, if portability trumps thread-safety, should
    unset the TZ environment variable.

  Changes to commentary

    The Îles-de-la-Madeleine and the Listuguj reserve are noted as
    following America/Halifax, and comments about Yukon's "south" and
    "north" have been corrected to say "east" and "west".  (Thanks to
    Jeffery Nichols.)


Release 2019c - 2019-09-11 08:59:48 -0700

  Briefly:
    Fiji observes DST from 2019-11-10 to 2020-01-12.
    Norfolk Island starts observing Australian-style DST.

  Changes to future timestamps

    Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
    instead of 2019-11-03 and 2020-01-19.  (Thanks to Raymond Kumar.)
    Adjust future guesses accordingly.

    Norfolk Island will observe Australian-style DST starting in
    spring 2019.  The first transition is on 2019-10-06.  (Thanks to
    Kyle Czech and Michael Deckers.)

  Changes to past timestamps

    Many corrections to time in Turkey from 1940 through 1985.
    (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)

    The Norfolk Island 1975-03-02 transition was at 02:00 standard
    time, not 02:00 DST.  (Thanks to Michael Deckers.)

    South Korea observed DST from 1948 through 1951.  Although this
    info was supposed to appear in release 2014j, a typo inadvertently
    suppressed the change.  (Thanks to Alois Treindl.)

    Detroit observed DST in 1967 and 1968 following the US DST rules,
    except that its 1967 DST began on June 14 at 00:01.  (Thanks to
    Alois Treindl for pointing out that the old data entries were
    probably wrong.)

    Fix several errors in pre-1970 transitions in Perry County, IN.
    (Thanks to Alois Triendl for pointing out the 1967/9 errors.)

    Edmonton did not observe DST in 1967 or 1969.  In 1946 Vancouver
    ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
    10-06.  In 1945 Königsberg (now Kaliningrad) switched from +01/+02
    to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
    EET/EEST, not CET/CEST.  (Thanks to Alois Triendl.)  In 1946
    Königsberg switched to +03 on 04-07 not 01-01.

    In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
    01-01 at 00:00.  (Thanks to Alois Treindl and Michael Deckers.)
    Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.

    The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
    (Thanks to Michael Deckers.)

  Changes to past time zone abbreviations and DST flags

    Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
    is now flagged as DST and is abbreviated HKWT not HKT.

  Changes to code

    leapseconds.awk now relies only on its input data, rather than
    also relying on its comments.  (Inspired by code from Dennis
    Ferguson and Chris Woodbury.)

    The code now defends against CRLFs in leap-seconds.list.
    (Thanks to Brian Inglis and Chris Woodbury.)

  Changes to documentation and commentary

    theory.html discusses leap seconds.  (Thanks to Steve Summit.)

    Nashville's newspapers dueled about the time of day in the 1950s.
    (Thanks to John Seigenthaler.)

    Liechtenstein observed Swiss DST in 1941/2.
    (Thanks to Alois Treindl.)


Release 2019b - 2019-07-01 00:09:53 -0700

  Briefly:
    Brazil no longer observes DST.
    'zic -b slim' outputs smaller TZif files; please try it out.
    Palestine's 2019 spring-forward transition was on 03-29, not 03-30.

  Changes to future timestamps

    Brazil has canceled DST and will stay on standard time indefinitely.
    (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
    Oliveira.)

    Predictions for Morocco now go through 2087 instead of 2037, to
    work around a problem on newlib when using TZif files output by
    zic 2019a or earlier.  (Problem reported by David Gauchard.)

  Changes to past and future timestamps

    Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
    at 01:00.  (Thanks to Sharef Mustafa and Even Scharning.)  Guess
    future transitions to be March's last Friday at 00:00.

  Changes to past timestamps

    Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
    03:30.  Its 1945 transition from JST to HKT was on 11-18 at 02:00,
    not 09-15 at 00:00.  In 1946 its spring-forward transition was on
    04-21 at 00:00, not the previous day at 03:30.  From 1946 through
    1952 its fall-back transitions occurred at 04:30, not at 03:30.
    In 1947 its fall-back transition was on 11-30, not 12-30.
    (Thanks to P Chan.)

  Changes to past time zone abbreviations

    Italy's 1866 transition to Rome Mean Time was on December 12, not
    September 22.  This affects only the time zone abbreviation for
    Europe/Rome between those dates.  (Thanks to Stephen Trainor and
    Luigi Rosa.)

  Changes affecting metadata only

    Add info about the Crimea situation in zone1970.tab and zone.tab.
    (Problem reported by Serhii Demediuk.)

  Changes to code

    zic's new -b option supports a way to control data bloat and to
    test for year-2038 bugs in software that reads TZif files.
    'zic -b fat' and 'zic -b slim' generate larger and smaller output;
    for example, changing from fat to slim shrinks the Europe/London
    file from 3648 to 1599 bytes, saving about 56%.  Fat and slim
    files represent the same set of timestamps and use the same TZif
    format as documented in tzfile(5) and in Internet RFC 8536.
    Fat format attempts to work around bugs or incompatibilities in
    older software, notably software that mishandles 64-bit TZif data
    or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
    Slim format is more efficient and does not work around 64-bit bugs
    or obsolete TZ strings.  Currently zic defaults to fat format
    unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
    out-of-the-box default is intended to change in future releases
    as the buggy software often mishandles timestamps anyway.

    zic no longer treats a set of rules ending in 2037 specially.
    Previously, zic assumed that such a ruleset meant that future
    timestamps could not be predicted, and therefore omitted a
    POSIX-like TZ string in the TZif output.  The old behavior is no
    longer needed for current tzdata, and caused problems with newlib
    when used with older tzdata (reported by David Gauchard).

    zic no longer generates some artifact transitions.  For example,
    Europe/London no longer has a no-op transition in January 1996.

  Changes to build procedure

    tzdata.zi now assumes zic 2017c or later.  This shrinks tzdata.zi
    by a percent or so.

  Changes to documentation and commentary

    The Makefile now documents the POSIXRULES macro as being obsolete,
    and similarly, zic's -p POSIXRULES option is now documented as
    being obsolete.  Although the POSIXRULES feature still exists and
    works as before, in practice it is rarely used for its intended
    purpose, and it does not work either in the default reference
    implementation (for timestamps after 2037) or in common
    implementations such as GNU/Linux (for contemporary timestamps).
    Since POSIXRULES was designed primarily as a temporary transition
    facility for System V platforms that died off decades ago, it is
    being decommissioned rather than institutionalized.

    New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).


Release 2019a - 2019-03-25 22:01:33 -0700

  Briefly:
    Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
    Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.

  Changes to past and future timestamps

    Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
    previously predicted.  Adjust our prediction by guessing that spring
    transitions will be between 24 and 30 March, which matches recent practice
    since 2016.  (Thanks to Even Scharning and Tim Parenti.)

    Metlakatla ended its observance of Pacific standard time,
    rejoining Alaska Time, on 2019-01-20 at 02:00.  (Thanks to Ryan
    Stanley and Tim Parenti.)

  Changes to past timestamps

    Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
    (Thanks to Alois Treindl and Isaac Starkman.)

  Changes to time zone abbreviations

    Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
    of being a separate zone that generates the abbreviation "UCT",
    which nowadays is typically a typo.  (Problem reported by Isiah
    Meadows.)

  Changes to code

    zic now has an -r option to limit the time range of output data.
    For example, 'zic -r @1000000000' limits the output data to
    timestamps starting 1000000000 seconds after the Epoch.
    This helps shrink output size and can be useful for applications
    not needing the full timestamp history, such as TZDIST truncation;
    see Internet RFC 8536 section 5.1.  (Inspired by a feature request
    from Christopher Wong, helped along by bug reports from Wong and
    from Tim Parenti.)

  Changes to documentation

    Mention Internet RFC 8536 (February 2019), which documents TZif.

    tz-link.html now cites tzdata-meta
    <https://tzdata-meta.timtimeonline.com/>.


Release 2018i - 2018-12-30 11:05:43 -0800

  Briefly:
    São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.

  Changes to future timestamps

    Due to a change in government, São Tomé and Príncipe switches back
    from +01 to +00 on 2019-01-01 at 02:00.  (Thanks to Vadim
    Nasardinov and Michael Deckers.)


Release 2018h - 2018-12-23 17:59:32 -0800

  Briefly:
    Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
    New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
    Metlakatla, Alaska observes PST this winter only.
    Guess Morocco will continue to adjust clocks around Ramadan.
    Add predictions for Iran from 2038 through 2090.

  Changes to future timestamps

    Guess that Morocco will continue to fall back just before and
    spring forward just after Ramadan, the practice since 2012.
    (Thanks to Maamar Abdelkader.)  This means Morocco will observe
    negative DST during Ramadan in main and vanguard formats, and in
    rearguard format it stays in the +00 timezone and observes
    ordinary DST in all months other than Ramadan.  As before, extend
    this guesswork to the year 2037.  As a consequence, Morocco is
    scheduled to observe three DST transitions in some Gregorian years
    (e.g., 2033) due to the mismatch between the Gregorian and Islamic
    calendars.

    The table of exact transitions for Iranian DST has been extended.
    It formerly cut off before the year 2038 in a nod to 32-bit time_t.
    It now cuts off before 2091 as there is doubt about how the Persian
    calendar will treat 2091.  This change predicts DST transitions in
    2038-9, 2042-3, and 2046-7 to occur one day later than previously
    predicted.  As before, post-cutoff transitions are approximated.

  Changes to past and future timestamps

    Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
    +05 on 2018-12-21.  This is a zone split as Qostanay (aka
    Kostanay) did not switch, so create a zone Asia/Qostanay.

    Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
    It did not change clocks that day and remains on -08 this winter.
    (Thanks to Ryan Stanley.)  It will revert to the usual Alaska
    rules next spring, so this change affects only timestamps
    from 2018-11-04 through 2019-03-10.

  Change to past timestamps

    Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
    not 00:00.  I transcribed the time incorrectly from Shanks.
    (Thanks to Phake Nick.)

    Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
    (Thanks to Phake Nick.)

    Guam observed DST irregularly from 1959 through 1977.
    (Thanks to Phake Nick.)

    Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
    10-01 changed standard time to +08:30 (not +08).  Its transition
    back to +08 after WWII was on 1945-09-15, not the previous day.
    Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
    (Thanks to Phake Nick, Steve Allen, and Joseph Myers.)  Also,
    its 1952 fallback was on 11-02 (not 10-25).

    This release contains many changes to timestamps before 1946 due
    to Japanese possession or occupation of Pacific/Chuuk,
    Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
    Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
    (Thanks to Phake Nick.)

    Assume that the Spanish East Indies was like the Philippines and
    observed American time until the end of 1844.  This affects
    Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.

  Changes to past tm_isdst flags

    For the recent Morocco change, the tm_isdst flag should be 1 from
    2018-10-27 00:00 to 2018-10-28 03:00.  (Thanks to Michael Deckers.)
    Give a URL to the official decree.  (Thanks to Matt Johnson.)


Release 2018g - 2018-10-26 22:22:45 -0700

  Briefly:
    Morocco switches to permanent +01 on 2018-10-28.

  Changes to future timestamps

    Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
    so its clocks will not fall back as previously scheduled.
    (Thanks to Mohamed Essedik Najd and Brian Inglis.)

  Changes to code

    When generating TZif files with leap seconds, zic no longer uses a
    format that trips up older 32-bit clients, fixing a bug introduced
    in 2018f.  (Reported by Daniel Fischer.)  Also, the zic workaround
    for QTBUG-53071 now also works for TZif files with leap seconds.

    The translator to rearguard format now rewrites the line
    "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
    "Rule Japan 1948 1951 - Sep Sun>=9  1:00 0 S".
    This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
    and earlier.  (Reported by Christos Zoulas.)

  Changes to past time zone abbreviations

    Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
    This reverts to 2011h, as the abbreviation change in 2011i was
    likely inadvertent.

  Changes to documentation

    tzfile.5 has new sections on interoperability issues.


Release 2018f - 2018-10-18 00:14:18 -0700

  Briefly:
  Volgograd moves from +03 to +04 on 2018-10-28.
  Fiji ends DST 2019-01-13, not 2019-01-20.
  Most of Chile changes DST dates, effective 2019-04-06.

  Changes to future timestamps

    Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
    (Thanks to Alexander Fetisov and Stepan Golosunov.)

    Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
    predicted.  (Thanks to Raymond Kumar.)  Adjust future predictions
    accordingly.

    Most of Chile will end DST on the first Saturday in April at 24:00 mainland
    time, and resume DST on the first Saturday in September at 24:00 mainland
    time.  The changes are effective from 2019-04-06, and do not affect the
    Magallanes region modeled by America/Punta_Arenas.  (Thanks to Juan Correa
    and Tim Parenti.)  Adjust future predictions accordingly.

  Changes to past timestamps

    The 2018-05-05 North Korea 30-minute time zone change took place
    at 23:30 the previous day, not at 00:00 that day.

    China's 1988 spring-forward transition was on April 17, not
    April 10.  Its DST transitions in 1986/91 were at 02:00, not 00:00.
    (Thanks to P Chan.)

    Fix several issues for Macau before 1992.  Macau's pre-1904 LMT
    was off by 10 s.  Macau switched to +08 in 1904 not 1912, and
    temporarily switched to +09/+10 during World War II.  Macau
    observed DST in 1942/79, not 1961/80, and there were several
    errors for transition times and dates.  (Thanks to P Chan.)

    The 1948-1951 fallback transitions in Japan were at 25:00 on
    September's second Saturday, not at 24:00.  (Thanks to Phake Nick.)
    zic turns this into 01:00 on the day after September's second
    Saturday, which is the best that POSIX or C platforms can do.

    Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
    paper by Li Yu, replacing more-questionable data from Shanks.

  Changes to time zone abbreviations

    Use "PST" and "PDT" for Philippine time.  (Thanks to Paul Goyette.)

  Changes to code

    zic now always generates TZif files where time type 0 is used for
    timestamps before the first transition.  This simplifies the
    reading of TZif files and should not affect behavior of existing
    TZif readers because the same set of time types is used; only
    their internal indexes may have changed.  This affects only the
    legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
    EET, which previously used nonzero types for these timestamps.

    Because of the type 0 change, zic no longer outputs a dummy
    transition at time -2**59 (before the Big Bang), as clients should
    no longer need this to handle historical timestamps correctly.
    This reverts a change introduced in 2013d and shrinks most TZif
    files by a few bytes.

    zic now supports negative time-of-day in Rule and Leap lines, e.g.,
    "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
    occurs at 18:00 on the Saturday before the last Sunday in April.
    This behavior was documented in 2018a but the code did not
    entirely match the documentation.

    localtime.c no longer requires at least one time type in TZif
    files that lack transitions or have a POSIX-style TZ string.  This
    future-proofs the code against possible future extensions to the
    format that would allow TZif files with POSIX-style TZ strings and
    without transitions or time types.

    A read-access subscript error in localtime.c has been fixed.
    It could occur only in TZif files with timecnt == 0, something that
    does not happen in practice now but could happen in future versions.

    localtime.c no longer ignores TZif POSIX-style TZ strings that
    specify only standard time.  Instead, these TZ strings now
    override the default time type for timestamps after the last
    transition (or for all timestamps if there are no transitions),
    just as DST strings specifying DST have always done.

    leapseconds.awk now outputs "#updated" and "#expires" comments,
    and supports leap seconds at the ends of months other than June
    and December.  (Inspired by suggestions from Chris Woodbury.)

  Changes to documentation

    New restrictions: A Rule name must start with a character that
    is neither an ASCII digit nor "-" nor "+", and an unquoted name
    should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
    The latter restriction makes room for future extensions (a
    possibility noted by Tom Lane).

    tzfile.5 now documents what time types apply before the first and
    after the last transition, if any.

    Documentation now uses the spelling "timezone" for a TZ setting
    that determines timestamp history, and "time zone" for a
    geographic region currently sharing the same standard time.

    The name "TZif" is now used for the tz binary data format.

    tz-link.htm now mentions the A0 TimeZone Migration utilities.
    (Thanks to Aldrin Martoq for the link.)

  Changes to build procedure

    New 'make' target 'rearguard_tarballs' to build the rearguard
    tarball only.  This is a convenience on platforms that lack lzip
    if you want to build the rearguard tarball.  (Problem reported by
    Deborah Goldsmith.)

    tzdata.zi is now more stable from release to release.  (Problem
    noted by Tom Lane.)  It is also a bit shorter.

    tzdata.zi now can contain comment lines documenting configuration
    information, such as which data format was selected, which input
    files were used, and how leap seconds are treated.  (Problems
    noted by Lester Caine and Brian Inglis.)  If the Makefile defaults
    are used these comment lines are absent, for backward
    compatibility.  A redistributor intending to alter its copy of the
    files should also append "-LABEL" to the 'version' file's first
    line, where "LABEL" identifies the redistributor's change.


Release 2018e - 2018-05-01 23:42:51 -0700

  Briefly:

    North Korea switches back to +09 on 2018-05-05.
    The main format uses negative DST again, for Ireland etc.
    'make tarballs' now also builds a rearguard tarball.
    New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.

  Changes to past and future timestamps

    North Korea switches back from +0830 to +09 on 2018-05-05.
    (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
    and Tim Parenti.)

    Bring back the negative-DST changes of 2018a, except be more
    compatible with data parsers that do not support negative DST.
    Also, this now affects historical timestamps in Namibia and the
    former Czechoslovakia, not just Ireland.  The main format now uses
    negative DST to model timestamps in Europe/Dublin (from 1971 on),
    Europe/Prague (1946/7), and Africa/Windhoek (1994/2017).  This
    does not affect UT offsets, only time zone abbreviations and the
    tm_isdst flag.  Also, this does not affect rearguard or vanguard
    formats; effectively the main format now uses vanguard instead of
    rearguard format.  Data parsers that do not support negative DST
    can still use data from the rearguard tarball described below.

  Changes to build procedure

    The command 'make tarballs' now also builds the tarball
    tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
    except that it uses rearguard format intended for trailing-edge
    data parsers.

  Changes to data format and to code

    The SAVE column of Rule and Zone lines can now have an 's' or 'd'
    suffix, which specifies whether the adjusted time is standard time
    or daylight saving time.  If no suffix is given, daylight saving
    time is used if and only if the SAVE column is nonzero; this is
    the longstanding behavior.  Although this new feature is not used
    in tzdata, it could be used to specify the legal time in Namibia
    1994-2017, as opposed to the popular time (see below).

  Changes to past timestamps

    From 1994 through 2017 Namibia observed DST in winter, not summer.
    That is, it used negative DST, as Ireland still does.  This change
    does not affect UTC offsets; it affects only the tm_isdst flag and
    the abbreviation used during summer, which is now CAT, not WAST.
    Although (as noted by Michael Deckers) summer and winter time were
    both simply called "standard time" in Namibian law, in common
    practice winter time was considered to be DST (as noted by Stephen
    Colebourne).  The full effect of this change is only in vanguard
    and main format; in rearguard format, the tm_isdst flag is still
    zero in winter and nonzero in summer.

    In 1946/7 Czechoslovakia also observed negative DST in winter.
    The full effect of this change is only in vanguard and main
    formats; in rearguard format, it is modeled as plain GMT without
    daylight saving.  Also, the dates of some 1944/5 DST transitions
    in Czechoslovakia have been changed.


Release 2018d - 2018-03-22 07:05:46 -0700

  Briefly:

  Palestine starts DST a week earlier in 2018.
  Add support for vanguard and rearguard data consumers.
  Add subsecond precision to source data format, though not to data.

  Changes to future timestamps

    In 2018, Palestine starts DST on March 24, not March 31.
    Adjust future predictions accordingly.  (Thanks to Sharef Mustafa.)

  Changes to past and future timestamps

    Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
    at 04:00.  (Thanks to Steffen Thorsen.)

  Changes to past timestamps

    Historical transitions for Uruguay, represented by
    America/Montevideo, have been updated per official legal documents,
    replacing previous data mainly originating from the inventions of
    Shanks & Pottenger.  This has resulted in adjustments ranging from
    30 to 90 minutes in either direction over at least two dozen
    distinct periods ranging from one day to several years in length.
    A mere handful of pre-1991 transitions are unaffected; data since
    then has come from more reliable contemporaneous reporting.  These
    changes affect various timestamps in 1920-1923, 1936, 1939,
    1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
    Additionally, Uruguay's pre-standard-time UT offset has been
    adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
    match the location of the Observatory of the National Meteorological
    Institute in Montevideo.
    (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)

    Enderbury and Kiritimati skipped New Year's Eve 1994, not
    New Year's Day 1995.  (Thanks to Kerry Shetline.)

    Fix the 1912-01-01 transition for Portugal and its colonies.
    This transition was at 00:00 according to the new UT offset, not
    according to the old one.  Also assume that Cape Verde switched on
    the same date as the rest, not in 1907.  This affects
    Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
    Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
    (Thanks to Michael Deckers.)

    Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
    Turks & Caicos.

  Changes to past time zone abbreviations

    MMT took effect in Uruguay from 1908-06-10, not 1898-06-28.  There
    is no clock change associated with the transition.

  Changes to build procedure

    The new DATAFORM macro in the Makefile lets the installer choose
    among three source data formats.  The idea is to lessen downstream
    disruption when data formats are improved.

    * DATAFORM=vanguard installs from the latest, bleeding-edge
      format.  DATAFORM=main (the default) installs from the format
      used in the 'africa' etc. files.  DATAFORM=rearguard installs
      from a trailing-edge format.  Eventually, elements of today's
      vanguard format should move to the main format, and similarly
      the main format's features should eventually move to the
      rearguard format.

    * In the current version, the main and rearguard formats are
      identical and match that of 2018c, so this change does not
      affect default behavior.  The vanguard format currently contains
      one feature not in the main format: negative SAVE values.  This
      improves support for Ireland, which uses Irish Standard Time
      (IST, UTC+01) in summer and GMT (UTC) in winter.  tzcode has
      supported negative SAVE values for decades, and this feature
      should move to the main format soon.  However, it will not move
      to the rearguard format for quite some time because some
      downstream parsers do not support it.

    * The build procedure constructs three files vanguard.zi, main.zi,
      and rearguard.zi, one for each format.  Although the files
      represent essentially the same data, they may have minor
      discrepancies that users are not likely to notice.  The files
      are intended for downstream data consumers and are not
      installed.  Zoneinfo parsers that do not support negative SAVE values
      should start using rearguard.zi, so that they will be unaffected
      when the negative-DST feature moves from vanguard to main.
      Bleeding-edge Zoneinfo parsers that support the new features
      already can use vanguard.zi; in this respect, current tzcode is
      bleeding-edge.

    The Makefile should now be safe for parallelized builds, and 'make
    -j to2050new.tzs' is now much faster on a multiprocessor host
    with GNU Make.

    When built with -DSUPPRESS_TZDIR, the tzcode library no longer
    prepends TZDIR/ to file names that do not begin with '/'.  This is
    not recommended for general use, due to its security implications.
    (From a suggestion by Manuela Friedrich.)

  Changes to code

    zic now accepts subsecond precision in expressions like
    00:19:32.13, which is approximately the legal time of the
    Netherlands from 1835 to 1937.  However, because it is
    questionable whether the few recorded uses of non-integer offsets
    had subsecond precision in practice, there are no plans for tzdata
    to use this feature.  (Thanks to Steve Allen for pointing out
    the limitations of historical data in this area.)

    The code is a bit more portable to MS-Windows.  Installers can
    compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
    reserve identifiers like 'localtime'.  (Thanks to Manuela
    Friedrich.)

  Changes to documentation and commentary

    theory.html now outlines tzdb's extensions to POSIX's model for
    civil time, and has a section "POSIX features no longer needed"
    that lists POSIX API components that are now vestigial.
    (From suggestions by Steve Summit.)  It also better distinguishes
    time zones from tz regions.  (From a suggestion by Guy Harris.)

    Commentary is now more consistent about using the phrase "daylight
    saving time", to match the C name tm_isdst.  Daylight saving time
    need not occur in summer, and need not have a positive offset from
    standard time.

    Commentary about historical transitions in Uruguay has been expanded
    with links to many relevant legal documents.
    (Thanks to Tim Parenti.)

    Commentary now uses some non-ASCII characters with Unicode value
    less than U+0100, as they can be useful and should work even with
    older editors such as XEmacs.


Release 2018c - 2018-01-22 23:00:44 -0800

  Briefly:
  Revert Irish changes that relied on negative SAVE values.

  Changes to tm_isdst

    Revert the 2018a change to Europe/Dublin.  As before, this change
    does not affect UT offsets or abbreviations; it affects only
    whether timestamps are considered to be standard time or
    daylight-saving time, as expressed in the tm_isdst flag of C's
    struct tm type.  This reversion is intended to be a temporary
    workaround for problems discovered with downstream uses of
    releases 2018a and 2018b, which implemented Irish time by using
    negative SAVE values in the Eire rules of the 'europe' file.
    Although negative SAVE values have been part of tzcode for many
    years and are supported by many platforms, they were not
    documented before 2018a and ICU and OpenJDK do not currently
    support them.  A mechanism to export data to platforms lacking
    support for negative DST is planned to be developed before the
    change is reapplied.  (Problems reported by Deborah Goldsmith and
    Stephen Colebourne.)

  Changes to past timestamps

    Japanese DST transitions (1948-1951) were Sundays at 00:00, not
    Saturdays or Sundays at 02:00.  (Thanks to Takayuki Nikai.)

  Changes to build procedure

    The build procedure now works around mawk 1.3.3's lack of support
    for character class expressions.  (Problem reported by Ohyama.)


Release 2018b - 2018-01-17 23:24:48 -0800

  Briefly:
  Fix a packaging problem in tz2018a, which was missing 'pacificnew'.

  Changes to build procedure

    The distribution now contains the file 'pacificnew' again.
    This file was inadvertantly omitted in the 2018a distribution.
    (Problem reported by Matias Fonzo.)


Release 2018a - 2018-01-12 22:29:21 -0800

  Briefly:
  São Tomé and Príncipe switched from +00 to +01.
  Brazil's DST will now start on November's first Sunday.
  Ireland's standard time is now in the summer, not the winter.
  Use Debian-style installation locations, instead of 4.3BSD-style.
  New zic option -t.

  Changes to past and future timestamps

    São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
    01:00.  (Thanks to Steffen Thorsen and Michael Deckers.)

  Changes to future timestamps

    Starting in 2018 southern Brazil will begin DST on November's
    first Sunday instead of October's third Sunday.  (Thanks to
    Steffen Thorsen.)

  Changes to past timestamps

    A discrepancy of 4 s in timestamps before 1931 in South Sudan has
    been corrected.  The 'backzone' and 'zone.tab' files did not agree
    with the 'africa' and 'zone1970.tab' files.  (Problem reported by
    Michael Deckers.)

    The abbreviation invented for Bolivia Summer Time (1931-2) is now
    BST instead of BOST, to be more consistent with the convention
    used for Latvian Summer Time (1918-9) and for British Summer Time.

  Changes to tm_isdst

    Change Europe/Dublin so that it observes Irish Standard Time (UT
    +01) in summer and GMT (as negative daylight-saving) in winter,
    instead of observing standard time (GMT) in winter and Irish
    Summer Time (UT +01) in summer.  This change does not affect UT
    offsets or abbreviations; it affects only whether timestamps are
    considered to be standard time or daylight-saving time, as
    expressed in the tm_isdst flag of C's struct tm type.
    (Discrepancy noted by Derick Rethans.)

  Changes to build procedure

    The default installation locations have been changed to mostly
    match Debian circa 2017, instead of being designed as an add-on to
    4.3BSD circa 1986.  This affects the Makefile macros TOPDIR,
    TZDIR, MANDIR, and LIBDIR.  New Makefile macros TZDEFAULT, USRDIR,
    USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
    locations more precisely.  (This responds to suggestions from
    Brian Inglis and from Steve Summit.)

    The default installation procedure no longer creates the
    backward-compatibility link US/Pacific-New, which causes
    confusion during user setup (e.g., see Debian bug 815200).
    Use 'make BACKWARD="backward pacificnew"' to create the link
    anyway, for now.  Eventually we plan to remove the link entirely.

    tzdata.zi now contains a version-number comment.
    (Suggested by Tom Lane.)

    The Makefile now quotes values like BACKWARD more carefully when
    passing them to the shell.  (Problem reported by Zefram.)

    Builders no longer need to specify -DHAVE_SNPRINTF on platforms
    that have snprintf and use pre-C99 compilers.  (Problem reported
    by Jon Skeet.)

  Changes to code

    zic has a new option -t FILE that specifies the location of the
    file that determines local time when TZ is unset.  The default for
    this location can be configured via the new TZDEFAULT makefile
    macro, which defaults to /etc/localtime.

    Diagnostics and commentary now distinguish UT from UTC more
    carefully; see theory.html for more information about UT vs UTC.

    zic has been ported to GCC 8's -Wstringop-truncation option.
    (Problem reported by Martin Sebor.)

  Changes to documentation and commentary

    The zic man page now documents the longstanding behavior that
    times and years can be out of the usual range, with negative times
    counting backwards from midnight and with year 0 preceding year 1.
    (Problem reported by Michael Deckers.)

    The theory.html file now mentions the POSIX limit of six chars
    per abbreviation, and lists alphabetic abbreviations used.

    The files tz-art.htm and tz-link.htm have been renamed to
    tz-art.html and tz-link.html, respectively, for consistency with
    other file names and to simplify web server configuration.


Release 2017c - 2017-10-20 14:49:34 -0700

  Briefly:
  Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
  Fiji ends DST 2018-01-14, not 2018-01-21.
  Namibia switches from +01/+02 to +02 on 2018-04-01.
  Sudan switches from +03 to +02 on 2017-11-01.
  Tonga likely switches from +13/+14 to +13 on 2017-11-05.
  Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
  A new file tzdata.zi now holds a small text copy of all data.
  The zic input format has been regularized slightly.

  Changes to future timestamps

    Northern Cyprus has decided to resume EU rules starting
    2017-10-29, thus reinstituting winter time.

    Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
    predicted.  (Thanks to Dominic Fok.)  Adjust future predictions
    accordingly.

    Namibia will switch from +01 with DST to +02 all year on
    2017-09-03 at 02:00.  This affects UT offsets starting 2018-04-01
    at 02:00.  (Thanks to Steffen Thorsen.)

    Sudan will switch from +03 to +02 on 2017-11-01.  (Thanks to Ahmed
    Atyya and Yahia Abdalla.)  South Sudan is not switching, so
    Africa/Juba is no longer a link to Africa/Khartoum.

    Tonga has likely ended its experiment with DST, and will not
    adjust its clocks on 2017-11-05.  Although Tonga has not announced
    whether it will continue to observe DST, the IATA is assuming that
    it will not.  (Thanks to David Wade.)

    Turks & Caicos will switch from -04 all year to -05 with US DST on
    2018-03-11 at 03:00.  This affects UT offsets starting 2018-11-04
    at 02:00.  (Thanks to Steffen Thorsen.)

  Changes to past timestamps

    Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
    (Thanks to Arthur David Olson.)

    Detroit did not observe DST in 1967.

    Use railway time for Asia/Kolkata before 1941, by switching to
    Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
    1906.  Also, treat 1941-2's +0630 as DST, like 1942-5.

    Europe/Dublin's 1946 and 1947 fallback transitions occurred at
    02:00 standard time, not 02:00 DST.  (Thanks to Michael Deckers.)

    Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
    American time in 1892, not 1879.  (Thanks to Michael Deckers.)

    Adjust the 1867 transition in Alaska to better reflect the
    historical record, by changing it to occur on 1867-10-18 at 15:30
    Sitka time rather than at the start of 1867-10-17 local time.
    Although strictly speaking this is accurate only for Sitka,
    the rest of Alaska's blanks need to be filled in somehow.

    Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
    (Thanks to Michael Deckers.)

    Add 7 s to the UT offset in Asia/Yangon before 1920.

  Changes to zone names

    Remove Canada/East-Saskatchewan from the 'backward' file, as it
    exceeded the 14-character limit and was an unused misnomer anyway.

  Changes to build procedure

    To support applications that prefer to read time zone data in text
    form, two zic input files tzdata.zi and leapseconds are now
    installed by default.  The commands 'zic tzdata.zi' and 'zic -L
    leapseconds tzdata.zi' can reproduce the tzdata binary files
    without and with leap seconds, respectively.  To prevent these two
    new files from being installed, use 'make TZDATA_TEXT=', and to
    suppress leap seconds from the tzdata text installation, use 'make
    TZDATA_TEXT=tzdata.zi'.

    'make BACKWARD=' now suppresses backward-compatibility names
    like 'US/Pacific' that are defined in the 'backward' and
    'pacificnew' files.

    'make check' now works on systems that lack a UTF-8 locale,
    or that lack the nsgmls program.  Set UTF8_LOCALE to configure
    the name of a UTF-8 locale, if you have one.

    Y2K runtime checks are no longer enabled by default.  Add
    -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
    adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
    to disable them.  (New name suggested by Brian Inglis.)

    The build procedure for zdump now works on AIX 7.1.
    (Problem reported by Kees Dekker.)

  Changes to code

    zic and the reference runtime now reject multiple leap seconds
    within 28 days of each other, or leap seconds before the Epoch.
    As a result, support for double leap seconds, which was
    obsolescent and undocumented, has been removed.  Double leap
    seconds were an error in the C89 standard; they have never existed
    in civil timekeeping.  (Thanks to Robert Elz and Bradley White for
    noticing glitches in the code that uncovered this problem.)

    zic now warns about use of the obsolescent and undocumented -y
    option, and about use of the obsolescent TYPE field of Rule lines.

    zic now allows unambiguous abbreviations like "Sa" and "Su" for
    weekdays; formerly it rejected them due to a bug.  Conversely, zic
    no longer considers non-prefixes to be abbreviations; for example,
    it no longer accepts "lF" as an abbreviation for "lastFriday".
    Also, zic warns about the undocumented usage with a "last-"
    prefix, e.g., "last-Fri".

    Similarly, zic now accepts the unambiguous abbreviation "L" for
    "Link" in ordinary context and for "Leap" in leap-second context.
    Conversely, zic no longer accepts non-prefixes such as "La" as
    abbreviations for words like "Leap".

    zic no longer accepts leap second lines in ordinary input, or
    ordinary lines in leap second input.  Formerly, zic sometimes
    warned about this undocumented usage and handled it incorrectly.

    The new macro HAVE_TZNAME governs whether the tzname external
    variable is exported, instead of USG_COMPAT.  USG_COMPAT now
    governs only the external variables "timezone" and "daylight".
    This change is needed because the three variables are not in the
    same category: although POSIX requires tzname, it specifies the
    other two variables as optional.  Also, USG_COMPAT is now 1 or 0:
    if not defined, the code attempts to guess it from other macros.

    localtime.c and difftime.c no longer require stdio.h, and .c files
    other than zic.c no longer require sys/wait.h.

    zdump.c no longer assumes snprintf.  (Reported by Jonathan Leffler.)

    Calculation of time_t extrema works around a bug in GCC 4.8.4
    (Reported by Stan Shebs and Joseph Myers.)

    zic.c no longer mistranslates formats of line numbers in non-English
    locales.  (Problem reported by Benno Schulenberg.)

    Several minor changes have been made to the code to make it a
    bit easier to port to MS-Windows and Solaris.  (Thanks to Kees
    Dekker for reporting the problems.)

  Changes to documentation and commentary

    The two new files 'theory.html' and 'calendars' contain the
    contents of the removed file 'Theory'.  The goal is to document
    tzdb theory more accessibly.

    The zic man page now documents abbreviation rules.

    tz-link.htm now covers how to apply tzdata changes to clients.
    (Thanks to Jorge Fábregas for the AIX link.)  It also mentions MySQL.

    The leap-seconds.list URL has been updated to something that is
    more reliable for tzdb.  (Thanks to Tim Parenti and Brian Inglis.)

Release 2017b - 2017-03-17 07:30:38 -0700

  Briefly: Haiti has resumed DST.

  Changes to past and future timestamps

    Haiti resumed observance of DST in 2017.  (Thanks to Steffen Thorsen.)

  Changes to past timestamps

    Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.

    Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
    is one byte over the POSIX limit.  (Problem reported by Derick Rethans.)

  Changes to code

    The reference localtime implementation now falls back on the
    current US daylight-saving transition rules rather than the
    1987-2006 rules.  This fallback occurs only when (1) the TZ
    environment variable has a value like "AST4ADT" that asks
    for daylight saving time but does not specify the rules, (2) there
    is no file by that name, and (3) the TZDEFRULES file cannot be
    loaded.  (Thanks to Tom Lane.)


Release 2017a - 2017-02-28 00:05:36 -0800

  Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
  discontinues DST.

  Changes to future timestamps

    Mongolia no longer observes DST.  (Thanks to Ganbold Tsagaankhuu.)

    Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
    Its clocks diverge from America/Santiago starting 2017-05-13 at
    23:00, hiving off a new zone America/Punta_Arenas.  Although the
    Chilean government says this change expires in May 2019, for now
    assume it's permanent.  (Thanks to Juan Correa and Deborah
    Goldsmith.)  This also affects Antarctica/Palmer.

  Changes to past timestamps

    Fix many entries for historical timestamps for Europe/Madrid
    before 1979, to agree with tables compiled by Pere Planesas of the
    National Astronomical Observatory of Spain.  As a side effect,
    this changes some timestamps for Africa/Ceuta before 1929, which
    are probably guesswork anyway.  (Thanks to Steve Allen and
    Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
    correcting the 1901 transition.)

    Ecuador observed DST from 1992-11-28 to 1993-02-05.
    (Thanks to Alois Treindl.)

    Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
    (Thanks to Stepan Golosunov.)

  Changes to past and future time zone abbreviations

    Switch to numeric time zone abbreviations for South America, as
    part of the ongoing project of removing invented abbreviations.
    This avoids the need to invent an abbreviation for the new Chilean
    new zone.  Similarly, switch from invented to numeric time zone
    abbreviations for Afghanistan, American Samoa, the Azores,
    Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
    Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
    Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
    Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
    the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
    Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
    Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
    Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
    Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
    Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
    for half-hour daylight saving time in Belize before 1944 and in
    the Dominican Republic before 1975; and for Canary Islands before
    1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
    Indian Summer Time before 1942, for Indonesia before around 1964,
    for Kenya before 1960, for Liberia before 1973, for Madeira before
    1967, for Namibia before 1943, for the Netherlands in 1937-9, for
    Pakistan before 1971, for Western Sahara before 1977, and for
    Zaporozhye in 1880-1924.

    For Alaska time from 1900 through 1967, instead of "CAT" use the
    abbreviation "AST", the abbreviation commonly used at the time
    (Atlantic Standard Time had not been standardized yet).  Use "AWT"
    and "APT" instead of the invented abbreviations "CAWT" and "CAPT".

    Use "CST" and "CDT" instead of invented abbreviations for Macau
    before 1999 and Taiwan before 1938, and use "JST" instead of the
    invented abbreviation "JCST" for Japan and Korea before 1938.

  Change to database entry category

    Move the Pacific/Johnston link from 'australasia' to 'backward',
    since Johnston is now uninhabited.

  Changes to code

    zic no longer mishandles some transitions in January 2038 when it
    attempts to work around Qt bug 53071.  This fixes a bug affecting
    Pacific/Tongatapu that was introduced in zic 2016e.  localtime.c
    now contains a workaround, useful when loading a file generated by
    a buggy zic.  (Problem and localtime.c fix reported by Bradley
    White.)

    zdump -i now outputs non-hour numeric time zone abbreviations
    without a colon, e.g., "+0530" rather than "+05:30".  This agrees
    with zic %z and with common practice, and simplifies auditing of
    zdump output.

    zdump is now buildable again with -DUSE_LTZ=0.
    (Problem reported by Joseph Myers.)

    zdump.c now always includes private.h, to avoid code duplication
    with private.h.  (Problem reported by Kees Dekker.)

    localtime.c no longer mishandles early or late timestamps
    when TZ is set to a POSIX-style string that specifies DST.
    (Problem reported by Kees Dekker.)

    date and strftime now cause %z to generate "-0000" instead of
    "+0000" when the UT offset is zero and the time zone abbreviation
    begins with "-".

  Changes to documentation and commentary

    The 'Theory' file now better documents choice of historical time
    zone abbreviations.  (Problems reported by Michael Deckers.)

    tz-link.htm now covers leap smearing, which is popular in clouds.


Release 2016j - 2016-11-22 23:17:13 -0800

  Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.

  Changes to future timestamps

    Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
    This hives off a new zone Europe/Saratov from Europe/Volgograd.
    (Thanks to Yuri Konotopov and Stepan Golosunov.)

  Changes to past timestamps

    The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
    Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
    1999, not fall 1994.  (Thanks to Stepan Golosunov.)

  Changes to past time zone abbreviations

    Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
    summer time before 1948.  The old use of "EET" was a typo.

  Changes to code

    zic no longer mishandles file systems that lack hard links, fixing
    bugs introduced in 2016g.  (Problems reported by Tom Lane.)
    Also, when the destination already contains symbolic links, zic
    should now work better on systems where the 'link' system call
    does not follow symbolic links.

  Changes to documentation and commentary

    tz-link.htm now documents the relationship between release version
    numbers and development-repository commit tags.  (Suggested by
    Paul Koning.)

    The 'Theory' file now documents UT.

    iso3166.tab now accents "Curaçao", and commentary now mentions
    the names "Cabo Verde" and "Czechia".  (Thanks to Jiří Boháč.)


Release 2016i - 2016-11-01 23:19:52 -0700

  Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
  reintroduces DST on 2016-11-06.

  Changes to future timestamps

    Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
    2017-01-15 at 03:00.  Assume future observances in Tonga will be
    from the first Sunday in November through the third Sunday in
    January, like Fiji.  (Thanks to Pulu ʻAnau.)  Switch to numeric
    time zone abbreviations for this zone.

  Changes to past and future timestamps

    Northern Cyprus is now +03 year round, causing a split in Cyprus
    time zones starting 2016-10-30 at 04:00.  This creates a zone
    Asia/Famagusta.  (Thanks to Even Scharning and Matt Johnson.)

    Antarctica/Casey switched from +08 to +11 on 2016-10-22.
    (Thanks to Steffen Thorsen.)

  Changes to past timestamps

    Several corrections were made for pre-1975 timestamps in Italy.
    These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
    Europe/Vatican.

    First, the 1893-11-01 00:00 transition in Italy used the new UT
    offset (+01), not the old (+00:49:56).  (Thanks to Michael
    Deckers.)

    Second, rules for daylight saving in Italy were changed to agree
    with Italy's National Institute of Metrological Research (INRiM)
    except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
    Inglis, and Michael Deckers):

      The 1916-06-03 transition was at 24:00, not 00:00.

      The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
      00:00, not 01:00.

      The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
      01:00.

      The 1944-09-17 transition was at 03:00, not 01:00.  This
      particular change is taken from Italian law as INRiM's table,
      (which says 02:00) appears to have a typo here.  Also, keep the
      1944-04-03 transition for Europe/Rome, as Rome was controlled by
      Germany then.

      The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
      not 00:00.

  Changes to code

    The code should now be buildable on AmigaOS merely by setting the
    appropriate Makefile variables.  (From a patch by Carsten Larsen.)


Release 2016h - 2016-10-19 23:17:57 -0700

  Changes to future timestamps

    Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
    2016-10-21 at 00:00.  (Thanks to Sharef Mustafa.)  Predict that
    future fall transitions will be on the last Saturday of October
    at 01:00, which is consistent with predicted spring transitions
    on the last Saturday of March.  (Thanks to Tim Parenti.)

  Changes to past timestamps

    In Turkey, transitions in 1986-1990 were at 01:00 standard time
    not at 02:00, and the spring 1994 transition was on March 20, not
    March 27.  (Thanks to Kıvanç Yazan.)

  Changes to past and future time zone abbreviations

    Asia/Colombo now uses numeric time zone abbreviations like "+0530"
    instead of alphabetic ones like "IST" and "LKT".  Various
    English-language sources use "IST", "LKT" and "SLST", with no
    working consensus.  (Usage of "SLST" mentioned by Sadika
    Sumanapala.)

  Changes to code

    zic no longer mishandles relativizing file names when creating
    symbolic links like /etc/localtime, when these symbolic links
    are outside the usual directory hierarchy.  This fixes a bug
    introduced in 2016g.  (Problem reported by Andreas Stieger.)

  Changes to build procedure

    New rules 'traditional_tarballs' and 'traditional_signatures' for
    building just the traditional-format distribution.  (Requested by
    Deborah Goldsmith.)

    The file 'version' is now put into the tzdata tarball too.
    (Requested by Howard Hinnant.)

  Changes to documentation and commentary

    The 'Theory' file now has a section on interface stability.
    (Requested by Paul Koning.)  It also mentions features like
    tm_zone and localtime_rz that have long been supported by the
    reference code.

    tz-link.htm has improved coverage of time zone boundaries suitable
    for geolocation.  (Thanks to heads-ups from Evan Siroky and Matt
    Johnson.)

    The US commentary now mentions Allen and the "day of two noons".

    The Fiji commentary mentions the government's 2016-10-03 press
    release.  (Thanks to Raymond Kumar.)


Release 2016g - 2016-09-13 08:56:38 -0700

  Changes to future timestamps

    Turkey switched from EET/EEST (+02/+03) to permanent +03,
    effective 2016-09-07.  (Thanks to Burak AYDIN.)  Use "+03" rather
    than an invented abbreviation for the new time.

    New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
    (Thanks to Tim Parenti.)

  Changes to past timestamps

    For America/Los_Angeles, spring-forward transition times have been
    corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
    1950-1966.

    For zones using Soviet time on 1919-07-01, transitions to UT-based
    time were at 00:00 UT, not at 02:00 local time.  The affected
    zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
    Europe/Ulyanovsk.  (Thanks to Alexander Belopolsky.)

  Changes to past and future time zone abbreviations

    The Factory zone now uses the time zone abbreviation -00 instead
    of a long English-language string, as -00 is now the normal way to
    represent an undefined time zone.

    Several zones in Antarctica and the former Soviet Union, along
    with zones intended for ships at sea that cannot use POSIX TZ
    strings, now use numeric time zone abbreviations instead of
    invented or obsolete alphanumeric abbreviations.  The affected
    zones are Antarctica/Casey, Antarctica/Davis,
    Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
    Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
    Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
    Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
    Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
    Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
    Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
    Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
    Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
    Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
    Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
    Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
    Europe/Minsk, Europe/Samara, Europe/Volgograd, and
    Indian/Kerguelen.  For Europe/Moscow the invented abbreviation MSM
    was replaced by +05, whereas MSK and MSD were kept as they are not
    our invention and are widely used.

  Changes to zone names

    Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
    (Thanks to David Massoud.)

  Changes to code

    zic no longer generates binary files containing POSIX TZ-like
    strings that disagree with the local time type after the last
    explicit transition in the data.  This fixes a bug with
    Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
    on the reference platform.  (Thanks to Alexander Belopolsky for
    reporting the bug and suggesting a way forward.)

    If the installed localtime and/or posixrules files are symbolic
    links, zic now keeps them symbolic links when updating them, for
    compatibility with platforms like OpenSUSE where other programs
    configure these files as symlinks.

    zic now avoids hard linking to symbolic links, avoids some
    unnecessary mkdir and stat system calls, and uses shorter file
    names internally.

    zdump has a new -i option to generate transitions in a
    more-compact but still human-readable format.  This option is
    experimental, and the output format may change in future versions.
    (Thanks to Jon Skeet for suggesting that an option was needed,
    and thanks to Tim Parenti and Chris Rovick for further comments.)

  Changes to build procedure

    An experimental distribution format is available, in addition
    to the traditional format which will continue to be distributed.
    The new format is a tarball tzdb-VERSION.tar.lz with signature
    file tzdb-VERSION.tar.lz.asc.  It unpacks to a top-level directory
    tzdb-VERSION containing the code and data of the traditional
    two-tarball format, along with extra data that may be useful.
    (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
    for comments about the experimental format.)

    The release version number is now more accurate in the usual case
    where releases are built from a Git repository.  For example, if
    23 commits and some working-file changes have been made since
    release 2016g, the version number is now something like
    '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
    Tagged releases use the same version number format as before,
    e.g., '2016g'.  To support the more-accurate version number, its
    specification has moved from a line in the Makefile to a new
    source file 'version'.

    The experimental distribution contains a file to2050.tzs that
    contains what should be the output of 'zdump -i -c 2050' on
    primary zones.  If this file is available, 'make check' now checks
    that zdump generates this output.

    'make check_web' now works on Fedora-like distributions.

  Changes to documentation and commentary

    tzfile.5 now documents the new restriction on POSIX TZ-like
    strings that is now implemented by zic.

    Comments now cite URLs for some 1917-1921 Russian DST decrees.
    (Thanks to Alexander Belopolsky.)

    tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
    (thanks to Meno Hochschild) and ThreeTen-Extra, and its
    description of Java 8 has been brought up to date (thanks to
    Stephen Colebourne).  Its description of local time on Mars has
    been updated to match current practice, and URLs have been updated
    and some obsolete ones removed.


Release 2016f - 2016-07-05 16:26:51 +0200

  Changes affecting future timestamps

    The Egyptian government changed its mind on short notice, and
    Africa/Cairo will not introduce DST starting 2016-07-07 after all.
    (Thanks to Mina Samuel.)

    Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
    (Thanks to Stepan Golosunov.)

  Changes to past and future timestamps

    Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
    abbreviations instead of invented ones.

  Changes affecting past timestamps

    Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
    (Thanks to Stepan Golosunov.)


Release 2016e - 2016-06-14 08:46:16 -0700

  Changes affecting future timestamps

    Africa/Cairo observes DST in 2016 from July 7 to the end of October.
    Guess October 27 and 24:00 transitions.  (Thanks to Steffen Thorsen.)
    For future years, guess April's last Thursday to October's last
    Thursday except for Ramadan.

  Changes affecting past timestamps

    Locations while uninhabited now use '-00', not 'zzz', as a
    placeholder time zone abbreviation.  This is inspired by Internet
    RFC 3339 and is more consistent with numeric time zone
    abbreviations already used elsewhere.  The change affects several
    arctic and antarctic locations, e.g., America/Cambridge_Bay before
    1920 and Antarctica/Troll before 2005.

    Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
    at 03:00, not 23:00 the previous day.  (Thanks to Michael Deckers.)

  Changes to code

    zic now outputs a dummy transition at time 2**31 - 1 in zones
    whose POSIX-style TZ strings contain a '<'.  This mostly works
    around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
    (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)

  Changes affecting documentation and commentary

    tz-link.htm says why governments should give plenty of notice for
    time zone or DST changes, and refers to Matt Johnson's blog post.

    tz-link.htm mentions Tzdata for Elixir.  (Thanks to Matt Johnson.)


Release 2016d - 2016-04-17 22:50:29 -0700

  Changes affecting future timestamps

    America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
    (Thanks to Alexander Krivenyshev for the heads-up.)

    Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
    (Thanks to Alexander Krivenyshev and Matt Johnson.)

    New zone Asia/Tomsk, split off from Asia/Novosibirsk.  It covers
    Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
    at 02:00.  (Thanks to Stepan Golosunov.)

  Changes affecting past timestamps

    New zone Europe/Kirov, split off from Europe/Volgograd.  It covers
    Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
    1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
    the same change.  (Thanks to Stepan Golosunov.)

    Russia and nearby locations had daylight-saving transitions on
    1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
    1992-03-28 at 23:00 and 1992-09-26 at 23:00.  (Thanks to Stepan
    Golosunov.)

    Many corrections to historical time in Kazakhstan from 1991
    through 2005.  (Thanks to Stepan Golosunov.)  Replace Kazakhstan's
    invented time zone abbreviations with numeric abbreviations.

  Changes to commentary

    Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).


Release 2016c - 2016-03-23 00:51:27 -0700

  Changes affecting future timestamps

    Azerbaijan no longer observes DST.  (Thanks to Steffen Thorsen.)

    Chile reverts from permanent to seasonal DST.  (Thanks to Juan
    Correa for the heads-up, and to Tim Parenti for corrections.)
    Guess that future transitions are August's and May's second
    Saturdays at 24:00 mainland time.  Also, call the period from
    2014-09-07 through 2016-05-14 daylight saving time instead of
    standard time, as that seems more appropriate now.

  Changes affecting past timestamps

    Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
    +02/+03 on 1989-03-26, not 1991-03-31.  Europe/Volgograd changed
    from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
    (Thanks to Stepan Golosunov.)

  Changes to commentary

    Several updates and URLs for historical and proposed Russian changes.
    (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)


Release 2016b - 2016-03-12 17:30:14 -0800

  Compatibility note

    Starting with release 2016b, some data entries cause zic implementations
    derived from tz releases 2005j through 2015e to issue warnings like
    "time zone abbreviation differs from POSIX standard (+03)".
    These warnings should not otherwise affect zic's output and can safely be
    ignored on today's platforms, as the warnings refer to a restriction in
    POSIX.1-1988 that was removed in POSIX.1-2001.  One way to suppress the
    warnings is to upgrade to zic derived from tz releases 2015f and later.

  Changes affecting future timestamps

    New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
    Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
    2016-03-27 at 02:00 local time.  They need distinct zones since their
    post-1970 histories disagree.  New zone Asia/Barnaul for Altai Krai and
    Altai Republic, Russia, which will switch from +06 to +07 on the same date
    and local time.  The Astrakhan change is already official; the others have
    passed the first reading in the State Duma and are extremely likely.
    Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
    (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
    and Stepan Golosunov for followup.)

    As a trial of a new system that needs less information to be made up,
    the new zones use numeric time zone abbreviations like "+04"
    instead of invented abbreviations like "ASTT".

    Haiti will not observe DST in 2016.  (Thanks to Jean Antoine via
    Steffen Thorsen.)

    Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
    (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
    Saturday at 01:00, not March's last Friday at 24:00.

  Changes affecting past timestamps

    Europe/Chisinau observed DST during 1990, and switched from +04 to
    +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
    (Thanks to Stepan Golosunov.)

    1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
    KUYT/KUYST.  (Thanks to Stepan Golosunov.)

  Changes to code

    tzselect's diagnostics and checking, and checktab.awk's checking,
    have been improved.  (Thanks to J William Piggott.)

    tzcode now builds under MinGW.  (Thanks to Ian Abbott and Esben Haabendal.)

    tzselect now tests Julian-date TZ settings more accurately.
    (Thanks to J William Piggott.)

  Changes to commentary

    Comments in zone tables have been improved.  (Thanks to J William Piggott.)

    tzselect again limits its menu comments so that menus fit on a
    24×80 alphanumeric display.

    A new web page tz-how-to.html.  (Thanks to Bill Seymour.)

    In the Theory file, the description of possible time zone abbreviations in
    tzdata has been cleaned up, as the old description was unclear and
    inconsistent.  (Thanks to Alain Mouette for reporting the problem.)


Release 2016a - 2016-01-26 23:28:02 -0800

  Changes affecting future timestamps

    America/Cayman will not observe daylight saving this year after all.
    Revert our guess that it would.  (Thanks to Matt Johnson.)

    Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
    (Thanks to Alexander Krivenyshev.)

    Asia/Tehran now has DST predictions for the year 2038 and later,
    to be March 21 00:00 to September 21 00:00.  This is likely better
    than predicting no DST, albeit off by a day every now and then.

  Changes affecting past and future timestamps

    America/Metlakatla switched from PST all year to AKST/AKDT on
    2015-11-01 at 02:00.  (Thanks to Steffen Thorsen.)

    America/Santa_Isabel has been removed, and replaced with a
    backward compatibility link to America/Tijuana.  Its contents were
    apparently based on a misreading of Mexican legislation.

  Changes affecting past timestamps

    Asia/Karachi's two transition times in 2002 were off by a minute.
    (Thanks to Matt Johnson.)

  Changes affecting build procedure

    An installer can now combine leap seconds with use of the backzone file,
    e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
    The old 'make posix_packrat' rule is now marked as obsolescent.
    (Thanks to Ian Abbott for an initial implementation.)

  Changes affecting documentation and commentary

    A new file LICENSE makes it easier to see that the code and data
    are mostly public-domain.  (Thanks to James Knight.)  The three
    non-public-domain files now use the current (3-clause) BSD license
    instead of older versions of that license.

    tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
    CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
    on editing tz source files (with a mention of Sublime zoneinfo,
    thanks to Gilmore Davidson).

    The Theory and asia files now mention the 2015 book "The Global
    Transformation of Time, 1870-1950", and cite a couple of reviews.

    The America/Chicago entry now documents the informal use of US
    central time in Fort Pierre, South Dakota.  (Thanks to Rick
    McDermid, Matt Johnson, and Steve Jones.)


Release 2015g - 2015-10-01 00:39:51 -0700

  Changes affecting future timestamps

    Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
    (Thanks to Fatih.)

    Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
    (Thanks to Alexander Krivenyshev.)

    Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
    (Thanks to Ken Rylander.)

    Fort Nelson, British Columbia will not fall back on 2015-11-01.  It has
    effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
    New zone America/Fort_Nelson.  (Thanks to Matt Johnson.)

  Changes affecting past timestamps

    Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.

  Changes affecting code

    localtime no longer mishandles America/Anchorage after 2037.
    (Thanks to Bradley White for reporting the bug.)

    On hosts with signed 32-bit time_t, localtime no longer mishandles
    Pacific/Fiji after 2038-01-16 14:00 UTC.

    The localtime module allows the variables 'timezone', 'daylight',
    and 'altzone' to be in common storage shared with other modules,
    and declares them in case the system <time.h> does not.
    (Problems reported by Kees Dekker.)

    On platforms with tm_zone, strftime.c now assumes it is not NULL.
    This simplifies the code and is consistent with zdump.c.
    (Problem reported by Christos Zoulas.)

  Changes affecting documentation

   The tzfile man page now documents that transition times denote the
   starts (not the ends) of the corresponding time periods.
   (Ambiguity reported by Bill Seymour.)


Release 2015f - 2015-08-10 18:06:56 -0700

  Changes affecting future timestamps

    North Korea switches to +0830 on 2015-08-15.  (Thanks to Steffen Thorsen.)
    The abbreviation remains "KST".  (Thanks to Robert Elz.)

    Uruguay no longer observes DST.  (Thanks to Steffen Thorsen
    and Pablo Camargo.)

  Changes affecting past and future timestamps

    Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
    (Thanks to Roman Tudos.)

  Changes affecting data format and code

    zic's '-y YEARISTYPE' option is no longer documented.  The TYPE
    field of a Rule line should now be '-'; the old values 'even',
    'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
    Although the implementation has not changed, these features do not
    work in the default installation, they are not used in the data,
    and they are now considered obsolescent.

    zic now checks that two rules don't take effect at the same time.
    (Thanks to Jon Skeet and Arthur David Olson.)  Constraints on
    simultaneity are now documented.

    The two characters '%z' in a zone format now stand for the UT
    offset, e.g., '-07' for seven hours behind UT and '+0530' for
    five hours and thirty minutes ahead.  This better supports time
    zone abbreviations conforming to POSIX.1-2001 and later.

  Changes affecting installed data files

    Comments for America/Halifax and America/Glace_Bay have been improved.
    (Thanks to Brian Inglis.)

    Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
    Europe/Sofia, and Europe/Tallinn.  This yields slightly smaller
    installed data files for Europe/Simferopol and Europe/Tallinn.
    It does not affect timestamps.  (Thanks to Howard Hinnant.)

  Changes affecting code

    zdump and zic no longer warn about valid time zone abbreviations
    like '-05'.

    Some Visual Studio 2013 warnings have been suppressed.
    (Thanks to Kees Dekker.)

    'date' no longer sets the time of day and its -a, -d, -n and -t
    options have been removed.  Long obsolescent, the implementation
    of these features had porting problems.  Builders no longer need
    to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
    (Thanks to Kees Dekker for pointing out the problem.)

  Changes affecting documentation

    The Theory file mentions naming issues earlier, as these seem to be
    poorly publicized (thanks to Gilmore Davidson for reporting the problem).

    tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).

    Mention that Herbert Samuel introduced the term "Summer Time".


Release 2015e - 2015-06-13 10:56:02 -0700

  Changes affecting future timestamps

    Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
    not 06-13 and 07-18 as we had guessed.  (Thanks to Milamber.)

    Assume Cayman Islands will observe DST starting next year, using US rules.
    Although it isn't guaranteed, it is the most likely.

  Changes affecting data format

    The file 'iso3166.tab' now uses UTF-8, so that its entries can better
    spell the names of Åland Islands, Côte d'Ivoire, and Réunion.

  Changes affecting code

    When displaying data, tzselect converts it to the current locale's
    encoding if the iconv command works.  (Problem reported by random832.)

    tzselect no longer mishandles Dominica, fixing a bug introduced
    in Release 2014f.  (Problem reported by Owen Leibman.)

    zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
    This fixes a bug introduced in Release 2014f.
    (Problem reported by Leonardo Chiquitto.)


Release 2015d - 2015-04-24 08:09:46 -0700

  Changes affecting future timestamps

    Egypt will not observe DST in 2015 and will consider canceling it
    permanently.  For now, assume no DST indefinitely.
    (Thanks to Ahmed Nazmy and Tim Parenti.)

  Changes affecting past timestamps

    America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
    1966-07-01.  Also, Yukon's time zone history is documented better.
    (Thanks to Brian Inglis and Dennis Ferguson.)

  Change affecting past and future time zone abbreviations

    The abbreviations for Hawaii-Aleutian standard and daylight times
    have been changed from HAST/HADT to HST/HDT, as per US Government
    Printing Office style.  This affects only America/Adak since 1983,
    as America/Honolulu was already using the new style.

  Changes affecting code

   zic has some minor performance improvements.


Release 2015c - 2015-04-11 08:55:55 -0700

  Changes affecting future timestamps

    Egypt's spring-forward transition is at 24:00 on April's last Thursday,
    not 00:00 on April's last Friday.  2015's transition will therefore be on
    Thursday, April 30 at 24:00, not Friday, April 24 at 00:00.  Similar fixes
    apply to 2026, 2037, 2043, etc.  (Thanks to Steffen Thorsen.)

  Changes affecting past timestamps

    The following changes affect some pre-1991 Chile-related timestamps
    in America/Santiago, Antarctica/Palmer, and Pacific/Easter.

      The 1910 transition was January 10, not January 1.

      The 1918 transition was September 10, not September 1.

      The UT -04 time observed from 1932 to 1942 is now considered to
      be standard time, not year-round DST.

      Santiago observed DST (UT -03) from 1946-07-15 through
      1946-08-31, then reverted to standard time, then switched to -05
      on 1947-04-01.

      Assume transitions before 1968 were at 00:00, since we have no data
      saying otherwise.

      The spring 1988 transition was 1988-10-09, not 1988-10-02.
      The fall 1990 transition was 1990-03-11, not 1990-03-18.

      Assume no UT offset change for Pacific/Easter on 1890-01-01,
      and omit all transitions on Pacific/Easter from 1942 through 1946
      since we have no data suggesting that they existed.

    One more zone has been turned into a link, as it differed
    from an existing zone only for older timestamps.  As usual,
    this change affects UT offsets in pre-1970 timestamps only.
    The zone's old contents have been moved to the 'backzone' file.
    The affected zone is America/Montreal.

  Changes affecting commentary

    Mention the TZUpdater tool.

    Mention "The Time Now".  (Thanks to Brandon Ramsey.)


Release 2015b - 2015-03-19 23:28:11 -0700

  Changes affecting future timestamps

    Mongolia will start observing DST again this year, from the last
    Saturday in March at 02:00 to the last Saturday in September at 00:00.
    (Thanks to Ganbold Tsagaankhuu.)

    Palestine will start DST on March 28, not March 27.  Also,
    correct the fall 2014 transition from September 26 to October 24.
    Adjust future predictions accordingly.  (Thanks to Steffen Thorsen.)

  Changes affecting past timestamps

    The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
    regression.  (Thanks to Stuart Bishop for reporting the problem.)

    Some more zones have been turned into links, when they differed
    from existing zones only for older timestamps.  As usual,
    these changes affect UT offsets in pre-1970 timestamps only.
    Their old contents have been moved to the 'backzone' file.
    The affected zones are: America/Antigua, America/Cayman,
    Pacific/Midway, and Pacific/Saipan.

  Changes affecting time zone abbreviations

    Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
    (Thanks to Hank W.)

  Changes affecting code

    Fix integer overflow bug in reference 'mktime' implementation.
    (Problem reported by Jörg Richter.)

    Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
    to be used in the same executable as standard-library time_t functions.
    (Problems reported by Bradley White.)

  Changes affecting commentary

    Cite the recent Mexican decree changing Quintana Roo's time zone.
    (Thanks to Carlos Raúl Perasso.)

    Likewise for the recent Chilean decree.  (Thanks to Eduardo Romero Urra.)

    Update info about Mars time.


Release 2015a - 2015-01-29 22:35:20 -0800

  Changes affecting future timestamps

    The Mexican state of Quintana Roo, represented by America/Cancun,
    will shift from Central Time with DST to Eastern Time without DST
    on 2015-02-01 at 02:00.  (Thanks to Steffen Thorsen and Gwillim Law.)

    Chile will not change clocks in April or thereafter; its new standard time
    will be its old daylight saving time.  This affects America/Santiago,
    Pacific/Easter, and Antarctica/Palmer.  (Thanks to Juan Correa.)

    New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
    (Thanks to Tim Parenti.)

  Changes affecting past timestamps

    Iceland observed DST in 1919 and 1921, and its 1939 fallback
    transition was Oct. 29, not Nov. 29.  Remove incorrect data from
    Shanks about time in Iceland between 1837 and 1908.

    Some more zones have been turned into links, when they differed
    from existing zones only for older timestamps.  As usual,
    these changes affect UT offsets in pre-1970 timestamps only.
    Their old contents have been moved to the 'backzone' file.
    The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
    and Asia/Muscat.

  Changes affecting code

    tzalloc now scrubs time zone abbreviations compatibly with the way
    that tzset always has, by replacing invalid bytes with '_' and by
    shortening too-long abbreviations.

    tzselect ports to POSIX awk implementations, no longer mishandles
    POSIX TZ settings when GNU awk is used, and reports POSIX TZ
    settings to the user.  (Thanks to Stefan Kuhn.)

  Changes affecting build procedure

    'make check' now checks for links to links in the data.
    One such link (for Africa/Asmera) has been fixed.
    (Thanks to Stephen Colebourne for pointing out the problem.)

  Changes affecting commentary

    The leapseconds file commentary now mentions the expiration date.
    (Problem reported by Martin Burnicki.)

    Update Mexican Library of Congress URL.


Release 2014j - 2014-11-10 17:37:11 -0800

  Changes affecting current and future timestamps

    Turks & Caicos' switch from US eastern time to UT -04 year-round
    did not occur on 2014-11-02 at 02:00.  It's currently scheduled
    for 2015-11-01 at 02:00.  (Thanks to Chris Walton.)

  Changes affecting past timestamps

    Many pre-1989 timestamps have been corrected for Asia/Seoul and
    Asia/Pyongyang, based on sources for the Korean-language Wikipedia
    entry for time in Korea.  (Thanks to Sanghyuk Jung.)  Also, no
    longer guess that Pyongyang mimicked Seoul time after World War II,
    as this is politically implausible.

    Some more zones have been turned into links, when they differed
    from existing zones only for older timestamps.  As usual,
    these changes affect UT offsets in pre-1970 timestamps only.
    Their old contents have been moved to the 'backzone' file.
    The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
    Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
    Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
    Indian/Mayotte.

  Changes affecting commentary

    The commentary is less enthusiastic about Shanks as a source,
    and is more careful to distinguish UT from UTC.


Release 2014i - 2014-10-21 22:04:57 -0700

  Changes affecting future timestamps

    Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
    (Thanks to Ken Rylander for the heads-up.)  Guess that future
    years will use a similar pattern.

    A new Zone Pacific/Bougainville, for the part of Papua New Guinea
    that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
    (Thanks to Kiley Walbom for the heads-up.)

  Changes affecting time zone abbreviations

    Since Belarus is not changing its clocks even though Moscow is,
    the time zone abbreviation in Europe/Minsk is changing from FET
    to its more-traditional value MSK on 2014-10-26 at 01:00.
    (Thanks to Alexander Bokovoy for the heads-up about Belarus.)

    The new abbreviation IDT stands for the pre-1976 use of UT +08 in
    Indochina, to distinguish it better from ICT (+07).

  Changes affecting past timestamps

    Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
    (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
    authoritative book).  Asia/Ho_Chi_Minh has been added to
    zone1970.tab, to give tzselect users in Vietnam two choices,
    since north and south Vietnam disagreed after our 1970 cutoff.

    Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
    they differed from existing zones only for older timestamps.  As
    usual, these changes affect pre-1970 timestamps only.  Their old
    contents have been moved to the 'backzone' file.

  Changes affecting code

    The time-related library functions now set errno on failure, and
    some crashes in the new tzalloc-related library functions have
    been fixed.  (Thanks to Christos Zoulas for reporting most of
    these problems and for suggesting fixes.)

    If USG_COMPAT is defined and the requested timestamp is standard time,
    the tz library's localtime and mktime functions now set the extern
    variable timezone to a value appropriate for that timestamp; and
    similarly for ALTZONE, daylight saving time, and the altzone variable.
    This change is a companion to the tzname change in 2014h, and is
    designed to make timezone and altzone more compatible with tzname.

    The tz library's functions now set errno to EOVERFLOW if they fail
    because the result cannot be represented.  ctime and ctime_r now
    return NULL and set errno when a timestamp is out of range, rather
    than having undefined behavior.

    Some bugs associated with the new 2014g functions have been fixed.
    This includes a bug that largely incapacitated the new functions
    time2posix_z and posix2time_z.  (Thanks to Christos Zoulas.)
    It also includes some uses of uninitialized variables after tzalloc.
    The new code uses the standard type 'ssize_t', which the Makefile
    now gives porting advice about.

  Changes affecting commentary

    Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).


Release 2014h - 2014-09-25 18:59:03 -0700

  Changes affecting past timestamps

    America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.

    Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
    not 1920-01-06.  The old entry was based on a misinterpretation of Shanks.

    Some more zones have been turned into links, when they differed
    from existing zones only for older timestamps.  As usual,
    these changes affect UT offsets in pre-1970 timestamps only.
    Their old contents have been moved to the 'backzone' file.
    The affected zones are: Africa/Blantyre, Africa/Bujumbura,
    Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
    Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.

  Changes affecting code

    zdump -V and -v now output gmtoff= values on all platforms,
    not merely on platforms defining TM_GMTOFF.

    The tz library's localtime and mktime functions now set tzname to a value
    appropriate for the requested timestamp, and zdump now uses this
    on platforms not defining TM_ZONE, fixing a 2014g regression.
    (Thanks to Tim Parenti for reporting the problem.)

    The tz library no longer sets tzname if localtime or mktime fails.

    zdump -c no longer mishandles transitions near year boundaries.
    (Thanks to Tim Parenti for reporting the problem.)

    An access to uninitialized data has been fixed.
    (Thanks to Jörg Richter for reporting the problem.)

    When THREAD_SAFE is defined, the code ports to the C11 memory model.
    A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
    and two threads race to initialize data used by gmtime-like functions.
    (Thanks to Andy Heninger for reporting the problems.)

  Changes affecting build procedure

    'make check' now checks better for properly-sorted data.

  Changes affecting documentation and commentary

    zdump's gmtoff=N output is now documented, and its isdst=D output
    is now documented to possibly output D values other than 0 or 1.

    zdump -c's treatment of years is now documented to use the
    Gregorian calendar and Universal Time without leap seconds,
    and its behavior at cutoff boundaries is now documented better.
    (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)

    Programs are now documented to use the proleptic Gregorian calendar.
    (Thanks to Alan Barrett for the suggestion.)

    Fractional-second GMT offsets have been documented for civil time
    in 19th-century Chennai, Jakarta, and New York.


Release 2014g - 2014-08-28 12:31:23 -0700

  Changes affecting future timestamps

    Turks & Caicos is switching from US eastern time to UT -04
    year-round, modeled as a switch on 2014-11-02 at 02:00.
    [As noted in 2014j, this switch was later delayed.]

  Changes affecting past timestamps

    Time in Russia or the USSR before 1926 or so has been corrected by
    a few seconds in the following zones: Asia/Irkutsk,
    Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
    Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara.  For
    Asia/Yekaterinburg the correction is a few minutes.  (Thanks to
    Vladimir Karpinsky.)

    The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
    This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
    Atlantic/Azores, and Atlantic/Madeira.  Also, Lisbon's pre-1912
    GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
    (Thanks to Stephen Colebourne for pointing to the decree.)

    Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.

    A new file 'backzone' contains data which may appeal to
    connoisseurs of old timestamps, although it is out of scope for
    the tz database, is often poorly sourced, and contains some data
    that is known to be incorrect.  The new file is not recommended
    for ordinary use and its entries are not installed by default.
    (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
    Isle of Man entries.)

    Some more zones have been turned into links, when they differed
    from existing zones only for older timestamps.  As usual,
    these changes affect UT offsets in pre-1970 timestamps only.
    Their old contents have been moved to the 'backzone' file.
    The affected zones are: Africa/Bangui, Africa/Brazzaville,
    Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
    Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.

  Changes affecting code

    Unless NETBSD_INSPIRED is defined to 0, the tz library now
    supplies functions for creating and using objects that represent
    timezones. The new functions are tzalloc, tzfree, localtime_rz,
    mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
    time2posix_z.  They are intended for performance: for example,
    localtime_rz (unlike localtime_r) is trivially thread-safe without
    locking.  (Thanks to Christos Zoulas for proposing NetBSD-inspired
    functions, and to Alan Barrett and Jonathan Lennox for helping to
    debug the change.)

    zdump now builds with the tz library unless USE_LTZ is defined to 0,
    This lets zdump use tz features even if the system library lacks them.
    To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
    TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.

    zdump now uses localtime_rz if available, as it's significantly faster,
    and it can help zdump better diagnose invalid timezone names.
    Define HAVE_LOCALTIME_RZ to 0 to suppress this.  HAVE_LOCALTIME_RZ
    defaults to 1 if NETBSD_INSPIRED && USE_LTZ.  When localtime_rz is
    not available, zdump now uses localtime_r and tzset if available,
    as this is a bit cleaner and faster than plain localtime.  Compile
    with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
    lacks these two functions.

    If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
    Although not needed for tz's own applications, which are single-threaded,
    this supports POSIX better if the tz library is used in multithreaded apps.

    Some crashes have been fixed when zdump or the tz library is given
    invalid or outlandish input.

    The tz library no longer mishandles leap seconds on platforms with
    unsigned time_t in timezones that lack ordinary transitions after 1970.

    The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
    already defined, to make it easier to configure on common platforms.
    Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.

    Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
    assumes that reading uninitialized memory yields garbage values
    but does not cause other problems such as traps.

    If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
    more likely to guess right for ambiguous timestamps near
    transitions where tm_isdst does not change.

    If HAVE_STRFTIME_L is defined to 1, the tz library now defines
    strftime_l for compatibility with recent versions of POSIX.
    Only the C locale is supported, though.  HAVE_STRFTIME_L defaults
    to 1 on recent POSIX versions, and to 0 otherwise.

    tzselect -c now uses a hybrid distance measure that works better
    in Africa.  (Thanks to Alan Barrett for noting the problem.)

    The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
    or when time_tz is defined.

    When HAVE_UTMPX_H is set the 'date' command now builds on systems
    whose <utmpx.h> file does not define WTMPX_FILE, and when setting
    the date it updates the wtmpx file if _PATH_WTMPX is defined.
    This affects GNU/Linux and similar systems.

    For easier maintenance later, some C code has been simplified,
    some lint has been removed, and the code has been tweaked so that
    plain 'make' is more likely to work.

    The C type 'bool' is now used for boolean values, instead of 'int'.

    The long-obsolete LOCALE_HOME code has been removed.

    The long-obsolete 'gtime' function has been removed.

  Changes affecting build procedure

    'zdump' no longer links in ialloc.o, as it's not needed.

    'make check_time_t_alternatives' no longer assumes GNU diff.

  Changes affecting distribution tarballs

    The files checktab.awk and zoneinfo2tdf.pl are now distributed in
    the tzdata tarball instead of the tzcode tarball, since they help
    maintain the data.  The NEWS and Theory files are now also
    distributed in the tzdata tarball, as they're relevant for data.
    (Thanks to Alan Barrett for pointing this out.)  Also, the
    leapseconds.awk file is no longer distributed in the tzcode
    tarball, since it belongs in the tzdata tarball (where 2014f
    inadvertently also distributed it).

  Changes affecting documentation and commentary

    A new file CONTRIBUTING is distributed.  (Thanks to Tim Parenti for
    suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
    for debugging it.)

    The man pages have been updated to use function prototypes,
    to document thread-safe variants like localtime_r, and to document
    the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
    mktime_z.

    The fields in Link lines have been renamed to be more descriptive
    and more like the parameters of 'ln'.  LINK-FROM has become TARGET,
    and LINK-TO has become LINK-NAME.

    tz-link.htm mentions the IETF's tzdist working group; Windows
    Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.

    Some broken URLs have been fixed in the commentary.  (Thanks to
    Lester Caine.)

    Commentary about Philippines DST has been updated, and commentary
    on pre-1970 time in India has been added.


Release 2014f - 2014-08-05 17:42:36 -0700

  Changes affecting future timestamps

    Russia will subtract an hour from most of its time zones on 2014-10-26
    at 02:00 local time.  (Thanks to Alexander Krivenyshev.)
    There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
    Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
    (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
    (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
    (Europe/Samara) are not changing their clocks.  The changed zones are
    Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
    Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
    Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
    Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
    subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
    but not its UTC offset.  Two zones are added: Asia/Chita (split
    from Asia/Yakutsk, and also with two hours subtracted) and
    Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
    subtracted).  (Thanks to Tim Parenti for much of the above.)

  Changes affecting time zone abbreviations

    Australian eastern time zone abbreviations are now AEST/AEDT not EST,
    and similarly for the other Australian zones.  That is, for eastern
    standard and daylight saving time the abbreviations are AEST and AEDT
    instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
    and AWST/AWDT are now used instead of the former CST, CWST, and WST.
    This change does not affect UT offsets, only time zone abbreviations.
    (Thanks to Rich Tibbett and many others.)

    Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
    effective 2014-10-26 at 02:00 local time.

    The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
    has been changed from URUT to XJT.  (Thanks to Luther Ma.)

    Prefer MSK/MSD for Moscow time in Russia, even in other cities.
    Similarly, prefer EET/EEST for eastern European time in Russia.

    Change time zone abbreviations in (western) Samoa to use "ST" and
    "DT" suffixes, as this is more likely to match common practice.
    Prefix "W" to (western) Samoa time when its standard-time offset
    disagrees with that of American Samoa.

    America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.

    Time zone abbreviations have been updated for Japan's two time
    zones used 1896-1937.  JWST now stands for Western Standard
    Time, and JCST for Central Standard Time (formerly this was CJT).
    These abbreviations are now used for time in Korea, Taiwan,
    and Sakhalin while controlled by Japan.

  Changes affecting past timestamps

    China's five zones have been simplified to two, since the post-1970
    differences in the other three seem to have been imaginary.  The
    zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
    removed; backwards-compatibility links still work, albeit with
    different behaviors for timestamps before May 1980.  Asia/Urumqi's
    1980 transition to UT +08 has been removed, so that it is now at
    +06 and not +08.  (Thanks to Luther Ma and to Alois Treindl;
    Treindl sent helpful translations of two papers by Guo Qingsheng.)

    Some zones have been turned into links, when they differed from existing
    zones only for older UT offsets where data entries were likely invented.
    These changes affect UT offsets in pre-1970 timestamps only.  This is
    similar to the change in release 2013e, except this time for western
    Africa.  The affected zones are: Africa/Bamako, Africa/Banjul,
    Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
    Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
    Atlantic/St_Helena.  This also affects the backwards-compatibility
    link Africa/Timbuktu.  (Thanks to Alan Barrett, Stephen Colebourne,
    Tim Parenti, and David Patte for reporting problems in earlier
    versions of this change.)

    Asia/Shanghai's pre-standard-time UT offset has been changed from
    8:05:57 to 8:05:43, the location of Xujiahui Observatory.  Its
    transition to standard time has been changed from 1928 to 1901.

    Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
    then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
    In 1946 it observed DST from 05-15 through 09-30; in 1947
    from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
    (Thanks to Yu-Cheng Chuang.)

    Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.

    Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
    10-03 at 00:00.  (Thanks to Konstantin Hyppönen.)

    Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
    period from 1911 to 1950.

    Pacific/Chatham has been changed to New Zealand standard time plus
    45 minutes for the period before 1957, reflecting a 1956 remark in
    the New Zealand parliament.

    Europe/Budapest has several pre-1946 corrections: in 1918 the transition
    out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
    1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
    not 04-06 at 02:00; and there was no DST in 1920.

    Africa/Accra is now assumed to have observed DST from 1920 through 1935.

    Time in Russia before 1927 or so has been corrected by a few seconds in
    the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
    Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
    Europe/Riga.  Also, Moscow's location has been changed to its Kilometer 0
    point.  (Thanks to Vladimir Karpinsky for the Moscow changes.)

  Changes affecting data format

    A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
    The new file's extended format allows multiple country codes per zone.
    The older file is still installed but is deprecated; its format is
    not changing and it will still be distributed for a while, but new
    applications should use the new file.

    The new file format simplifies maintenance of obscure locations.
    To test this, it adds coverage for the Crozet Islands and the
    Scattered Islands.  (Thanks to Tobias Conradi and Antoine Leca.)

    The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
    It is still ASCII now, but commentary about the switch has been added.
    The new file 'zone1970.tab' already uses UTF-8.

  Changes affecting code

    'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
    is defined.  (Thanks to Elliott Hughes for reporting the problem.)

    'zic' no longer mishandles input when ignoring case in locales that
    are not compatible with English, e.g., unibyte Turkish locales when
    compiled with HAVE_GETTEXT.

    Error diagnostics of 'zic' and 'yearistype' have been reworded so that
    they no longer use ASCII '-' as if it were a dash.

    'zic' now rejects output file names that contain '.' or '..' components.
    (Thanks to Tim Parenti for reporting the problem.)

    'zic -v' now warns about output file names that do not follow
    POSIX rules, or that contain a digit or '.'.  (Thanks to Arthur
    David Olson for starting the ball rolling on this.)

    Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.

  Changes affecting build procedure

    'zic' no longer links in localtime.o and asctime.o, as they're not needed.
    (Thanks to John Cochran.)

  Changes affecting documentation and commentary

    The 'Theory' file documents legacy names, the longstanding
    exceptions to the POSIX-inspired file name rules.

    The 'zic' documentation clarifies the role of time types when
    interpreting dates.  (Thanks to Arthur David Olson.)

    Documentation and commentary now prefer UTF-8 to US-ASCII,
    allowing the use of proper accents in foreign words and names.
    Code and data have not changed because of this.  (Thanks to
    Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
    this.)

    Non-HTML documentation and commentary now use plain-text URLs instead of
    HTML insertions, and are more consistent about bracketing URLs when they
    are not already surrounded by white space.  (Thanks to suggestions by
    Steffen Nurpmeso.)

    There is new commentary about Xujiahui Observatory, the five time-zone
    project in China from 1918 to 1949, timekeeping in Japanese-occupied
    Shanghai, and Tibet Time in the 1950s.  The sharp-eyed can spot the
    warlord Jin Shuren in the data.

    Commentary about the coverage of each Russian zone has been standardized.
    (Thanks to Tim Parenti.)

    There is new commentary about contemporary timekeeping in Ethiopia.

    Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.

    There is new commentary about time in Poland in 1919.

    Proper credit has been given to DST inventor George Vernon Hudson.

    Commentary about time in Metlakatla, AK and Resolute, NU has been
    improved, with a new source for the former.

    In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
    is uninhabited.

    Commentary about permanent Antarctic bases has been updated.

    Several typos have been corrected.  (Thanks to Tim Parenti for
    contributing some of these fixes.)

    tz-link.htm now mentions the JavaScript libraries Moment Timezone,
    TimezoneJS.Date, Walltime-js, and Timezone.  (Thanks to a heads-up
    from Matt Johnson.)  Also, it mentions the Go 'latlong' package.
    (Thanks to a heads-up from Dirkjan Ochtman.)

    The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
    have been removed.  These obsolescent US Naval Observatory entries were no
    longer helpful for maintenance.  (Thanks to Tim Parenti for the suggestion.)


Release 2014e - 2014-06-12 21:53:52 -0700

  Changes affecting near-future timestamps

    Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
    (Thanks to Imed Chihi.)  Guess that from 2015 on Egypt will temporarily
    switch to standard time at 24:00 the last Thursday before Ramadan, and
    back to DST at 00:00 the first Friday after Ramadan.

    Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00.  (Thanks
    to Milamber Space Network.)  Guess that from 2015 on Morocco will
    temporarily switch to standard time at 03:00 the last Saturday before
    Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.

  Changes affecting past timestamps

    The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
    "MSD" for Moscow's double daylight time in summer 1921.  Also, a typo
    "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
    in 1991.  (Thanks to Hank W. for reporting the problems.)

  Changes affecting commentary

    tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
    draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
    removes stale pointers to World Time Explorer and WORLDTIME.


Release 2014d - 2014-05-27 21:34:40 -0700

  Changes affecting code

    zic no longer generates files containing timestamps before the Big Bang.
    This works around GNOME glib bug 878
    <https://gitlab.gnome.org/GNOME/glib/issues/878>
    (Thanks to Leonardo Chiquitto for reporting the bug, and to
    Arthur David Olson and James Cloos for suggesting improvements to the fix.)

  Changes affecting documentation

    tz-link.htm now mentions GNOME.


Release 2014c - 2014-05-13 07:44:13 -0700

  Changes affecting near-future timestamps

    Egypt observes DST starting 2014-05-15 at 24:00.
    (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
    Details have not been announced, except that DST will not be observed
    during Ramadan.  Guess that DST will stop during the same Ramadan dates as
    Morocco, and that Egypt's future spring and fall transitions will be the
    same as 2010 when it last observed DST, namely April's last Friday at
    00:00 to September's last Thursday at 23:00 standard time.  Also, guess
    that Ramadan transitions will be at 00:00 standard time.

  Changes affecting code

    zic now generates transitions for minimum time values, eliminating guesswork
    when handling low-valued timestamps.  (Thanks to Arthur David Olson.)

    Port to Cygwin sans glibc.  (Thanks to Arthur David Olson.)

  Changes affecting commentary and documentation

    Remove now-confusing comment about Jordan.  (Thanks to Oleksii Nochovnyi.)


Release 2014b - 2014-03-24 21:28:50 -0700

  Changes affecting near-future timestamps

    Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
    (Thanks to Alexander Krivenyshev.)  Move its zone.tab entry from UA to RU.

    New entry for Troll station, Antarctica.  (Thanks to Paul-Inge Flakstad and
    Bengt-Inge Larsson.)  This is currently an approximation; a better version
    will require the zic and localtime fixes mentioned below, and the plan is
    to wait for a while until at least the zic fixes propagate.

  Changes affecting code

    'zic' and 'localtime' no longer reject locations needing four transitions
    per year for the foreseeable future.  (Thanks to Andrew Main (Zefram).)
    Also, 'zic' avoids some unlikely failures due to integer overflow.

  Changes affecting build procedure

    'make check' now detects Rule lines defined but never used.
    The NZAQ rules, an instance of this problem, have been removed.

  Changes affecting commentary and documentation

    Fix Tuesday/Thursday typo in description of time in Israel.
    (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)

    Microsoft Windows 8.1 doesn't support tz database names.  (Thanks
    to Donald MacQueen.)  Instead, the Microsoft Windows Store app
    library supports them.

    Add comments about Johnston Island time in the 1960s.
    (Thanks to Lyle McElhaney.)

    Morocco's 2014 DST start will be as predicted.
    (Thanks to Sebastien Willemijns.)


Release 2014a - 2014-03-07 23:30:29 -0800

  Changes affecting near-future timestamps

    Turkey begins DST on 2014-03-31, not 03-30.  (Thanks to Faruk Pasin for
    the heads-up, and to Tim Parenti for simplifying the update.)

  Changes affecting past timestamps

    Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
    (Thanks to Steffen Thorsen.)

    Ukraine switched from Moscow to Eastern European time on 1990-07-01
    (not 1992-01-01), and observed DST during the entire next winter.
    (Thanks to Vladimir in Moscow via Alois Treindl.)

    In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
    (Thanks to Avigdor Finkelstein.)

  Changes affecting code

    A uninitialized-storage bug in 'localtime' has been fixed.
    (Thanks to Logan Chien.)

  Changes affecting the build procedure

    The settings for 'make check_web' now default to Ubuntu 13.10.

  Changes affecting commentary and documentation

    The boundary of the US Pacific time zone is given more accurately.
    (Thanks to Alan Mintz.)

    Chile's 2014 DST will be as predicted.  (Thanks to José Miguel Garrido.)

    Paraguay's 2014 DST will be as predicted.  (Thanks to Carlos Raúl Perasso.)

    Better descriptions of countries with same time zone history as
    Trinidad and Tobago since 1970.  (Thanks to Alan Barrett for suggestion.)

    Several changes affect tz-link.htm, the main web page.

      Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
      David Braverman).

      Mention xCal (Internet RFC 6321) and jCal.

      Microsoft has some support for tz database names.

      CLDR data formats include both XML and JSON.

      Mention Maggiolo's map of solar vs standard time.
      (Thanks to Arthur David Olson.)

      Mention TZ4Net.  (Thanks to Matt Johnson.)

      Mention the timezone-olson Haskell package.

      Mention zeitverschiebung.net.  (Thanks to Martin Jäger.)

      Remove moribund links to daylight-savings-time.info and to
      Simple Timer + Clocks.

      Update two links.  (Thanks to Oscar van Vlijmen.)

      Fix some formatting glitches, e.g., remove random newlines from
      abbr elements' title attributes.


Release 2013i - 2013-12-17 07:25:23 -0800

  Changes affecting near-future timestamps:

    Jordan switches back to standard time at 00:00 on December 20, 2013.
    The 2006-2011 transition schedule is planned to resume in 2014.
    (Thanks to Steffen Thorsen.)

  Changes affecting past timestamps:

    In 2004, Cuba began DST on March 28, not April 4.
    (Thanks to Steffen Thorsen.)

  Changes affecting code

    The compile-time flag NOSOLAR has been removed, as nowadays the
    benefit of slightly shrinking runtime table size is outweighed by the
    cost of disallowing potential future updates that exceed old limits.

  Changes affecting documentation and commentary

    The files solar87, solar88, and solar89 are no longer distributed.
    They were a negative experiment - that is, a demonstration that
    tz data can represent solar time only with some difficulty and error.
    Their presence in the distribution caused confusion, as Riyadh
    civil time was generally not solar time in those years.

    tz-link.htm now mentions Noda Time.  (Thanks to Matt Johnson.)


Release 2013h - 2013-10-25 15:32:32 -0700

  Changes affecting current and future timestamps:

    Libya has switched its UT offset back to +02 without DST, instead
    of +01 with DST.  (Thanks to Even Scharning.)

    Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
    (Thanks to Gwillim Law.)

  Changes affecting future timestamps:

    Acre and (we guess) western Amazonas will switch from UT -04 to -05
    on 2013-11-10.  This affects America/Rio_Branco and America/Eirunepe.
    (Thanks to Steffen Thorsen.)

    Add entries for DST transitions in Morocco in the year 2038.
    This avoids some year-2038 glitches introduced in 2013g.
    (Thanks to Yoshito Umaoka for reporting the problem.)

  Changes affecting API

    The 'tzselect' command no longer requires the 'select' command,
    and should now work with /bin/sh on more platforms.  It also works
    around a bug in BusyBox awk before version 1.21.0.  (Thanks to
    Patrick 'P. J.' McDermott and Alan Barrett.)

  Changes affecting code

    Fix localtime overflow bugs with 32-bit unsigned time_t.

    zdump no longer assumes sscanf returns maximal values on overflow.

  Changes affecting the build procedure

    The builder can specify which programs to use, if any, instead of
    'ar' and 'ranlib', and libtz.a is now built locally before being
    installed.  (Thanks to Michael Forney.)

    A dependency typo in the 'zdump' rule has been fixed.
    (Thanks to Andrew Paprocki.)

    The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
    work as specified by POSIX.2-1992 or later; this is portable nowadays.

    'make clean' no longer removes 'leapseconds', since it's
    host-independent and is part of the distribution.

    The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.

  Changes affecting documentation and commentary

    tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
    (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).

    Update URLs in tz-link page.  Add URLs for Microsoft Windows, since
    8.1 introduces tz support.  Remove URLs for Tru64 and UnixWare (no
    longer maintained) and for old advisories.  SOFA now does C.

Release 2013g - 2013-09-30 21:08:26 -0700

  Changes affecting current and near-future timestamps

    Morocco now observes DST from the last Sunday in March to the last
    Sunday in October, not April to September respectively.  (Thanks
    to Steffen Thorsen.)

  Changes affecting 'zic'

    'zic' now runs on platforms that lack both hard links and symlinks.
    (Thanks to Theo Veenker for reporting the problem, for MinGW.)
    Also, fix some bugs on platforms that lack hard links but have symlinks.

    'zic -v' again warns that Asia/Tehran has no POSIX environment variable
    to predict the far future, fixing a bug introduced in 2013e.

  Changes affecting the build procedure

    The 'leapseconds' file is again put into the tzdata tarball.
    Also, 'leapseconds.awk', so tzdata is self-contained.  (Thanks to
    Matt Burgess and Ian Abbott.)  The timestamps of these and other
    dependent files in tarballs are adjusted more consistently.

  Changes affecting documentation and commentary

    The README file is now part of the data tarball as well as the code.
    It now states that files are public domain unless otherwise specified.
    (Thanks to Andrew Main (Zefram) for asking for clarifications.)
    Its details about the 1989 release moved to a place of honor near
    the end of NEWS.


Release 2013f - 2013-09-24 23:37:36 -0700

  Changes affecting near-future timestamps

    Tocantins will very likely not observe DST starting this spring.
    (Thanks to Steffen Thorsen.)

    Jordan will likely stay at UT +03 indefinitely, and will not fall
    back this fall.

    Palestine will fall back at 00:00, not 01:00.  (Thanks to Steffen Thorsen.)

  Changes affecting API

    The types of the global variables 'timezone' and 'altzone' (if present)
    have been changed back to 'long'.  This is required for 'timezone'
    by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
    These variables were originally 'long' in the tz code, but were
    mistakenly changed to 'time_t' in 1987; nobody reported the
    incompatibility until now.  The difference matters on x32, where
    'long' is 32 bits and 'time_t' is 64.  (Thanks to Elliott Hughes.)

  Changes affecting the build procedure

    Avoid long strings in leapseconds.awk to work around a mawk bug.
    (Thanks to Cyril Baurand.)

  Changes affecting documentation and commentary

    New file 'NEWS' that contains release notes like this one.

    Paraguay's law does not specify DST transition time; 00:00 is customary.
    (Thanks to Waldemar Villamayor-Venialbo.)

    Minor capitalization fixes.

  Changes affecting version-control only

    The experimental GitHub repository now contains annotated and
    signed tags for recent releases, e.g., '2013e' for Release 2013e.
    Releases are tagged starting with 2012e; earlier releases were
    done differently, and tags would either not have a simple name or
    not exactly match what was released.

    'make set-timestamps' is now simpler and a bit more portable.


Release 2013e - 2013-09-19 23:50:04 -0700

  Changes affecting near-future timestamps

    This year Fiji will start DST on October 27, not October 20.
    (Thanks to David Wheeler for the heads-up.)  For now, guess that
    Fiji will continue to spring forward the Sunday before the fourth
    Monday in October.

  Changes affecting current and future time zone abbreviations

    Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
    time zone abbreviations since 1932.  (Thanks to George Ziegler,
    Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
    Benny Lin.)  This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
    Asia/Makassar, and Asia/Pontianak.

    Use ART (UT -03, standard time), rather than WARST (also -03, but
    daylight saving time) for San Luis, Argentina since 2009.

  Changes affecting Godthåb timestamps after 2037 if version mismatch

    Allow POSIX-like TZ strings where the transition time's hour can
    range from -167 through 167, instead of the POSIX-required 0
    through 24.  E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
    new Fiji rules.  This is a more-compact way to represent
    far-future timestamps for America/Godthab, America/Santiago,
    Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
    Pacific/Easter, and Pacific/Fiji.  Other zones are unaffected by
    this change.  (Derived from a suggestion by Arthur David Olson.)

    Allow POSIX-like TZ strings where daylight saving time is in
    effect all year.  E.g., TZ='WART4WARST,J1/0,J365/25' for Western
    Argentina Summer Time all year.  This supports a more-compact way
    to represent the 2013d data for America/Argentina/San_Luis.
    Because of the change for San Luis noted above this change does not
    affect the current data.  (Thanks to Andrew Main (Zefram) for
    suggestions that improved this change.)

    Where these two TZ changes take effect, there is a minor extension
    to the tz file format in that it allows new values for the
    embedded TZ-format string, and the tz file format version number
    has therefore been increased from 2 to 3 as a precaution.
    Version-2-based client code should continue to work as before for
    all timestamps before 2038.  Existing version-2-based client code
    (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
    files, and typically works in practice even for timestamps after
    2037; the only known exception is America/Godthab.

  Changes affecting timestamps before 1970

    Pacific/Johnston is now a link to Pacific/Honolulu.  This corrects
    some errors before 1947.

    Some zones have been turned into links, when they differ from existing
    zones only in older data entries that were likely invented or that
    differ only in LMT or transitions from LMT.  These changes affect
    only timestamps before 1943.  The affected zones are:
    Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
    America/Grenada, America/Guadeloupe, America/Marigot,
    America/Montserrat, America/St_Barthelemy, America/St_Kitts,
    America/St_Lucia, America/St_Thomas, America/St_Vincent,
    America/Tortola, and Europe/Vaduz.  (Thanks to Alois Treindl for
    confirming that the old Europe/Vaduz zone was wrong and the new
    link is better for WWII-era times.)

    Change Kingston Mean Time from -5:07:12 to -5:07:11.  This affects
    America/Cayman, America/Jamaica and America/Grand_Turk timestamps
    from 1890 to 1912.

    Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
    This affects Europe/Zurich timestamps from 1853 to 1894.  (Thanks
    to Alois Treindl.)

    Change the date of the circa-1850 Zurich transition from 1849-09-12
    to 1853-07-16, overriding Shanks with data from Messerli about
    postal and telegraph time in Switzerland.

  Changes affecting time zone abbreviations before 1970

    For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
    as Jakarta was called Batavia back then.

  Changes affecting API

    The 'zic' command now outputs a dummy transition when far-future
    data can't be summarized using a TZ string, and uses a 402-year
    window rather than a 400-year window.  For the current data, this
    affects only the Asia/Tehran file.  It does not affect any of the
    timestamps that this file represents, so zdump outputs the same
    information as before.  (Thanks to Andrew Main (Zefram).)

    The 'date' command has a new '-r' option, which lets you specify
    the integer time to display, a la FreeBSD.

    The 'tzselect' command has two new options '-c' and '-n', which lets you
    select a zone based on latitude and longitude.

    The 'zic' command's '-v' option now warns about constructs that
    require the new version-3 binary file format.  (Thanks to Arthur
    David Olson for the suggestion.)

    Support for floating-point time_t has been removed.
    It was always dicey, and POSIX no longer requires it.
    (Thanks to Eric Blake for suggesting to the POSIX committee to
    remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
    Heninger, Arthur David Olson, and Alois Treindl, for reporting
    bugs and elucidating some of the corners of the old floating-point
    implementation.)

    The signatures of 'offtime', 'timeoff', and 'gtime' have been
    changed back to the old practice of using 'long' to represent UT
    offsets.  This had been inadvertently and mistakenly changed to
    'int_fast32_t'.  (Thanks to Christos Zoulas.)

    The code avoids undefined behavior on integer overflow in some
    more places, including gmtime, localtime, mktime and zdump.

  Changes affecting the zdump utility

    zdump now outputs "UT" when referring to Universal Time, not "UTC".
    "UTC" does not make sense for timestamps that predate the introduction
    of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
    for clarifying UT vs UTC.)

  Data changes affecting behavior of tzselect and similar programs

    Country code BQ is now called the more-common name "Caribbean Netherlands"
    rather than the more-official "Bonaire, St Eustatius & Saba".

    Remove from zone.tab the names America/Montreal, America/Shiprock,
    and Antarctica/South_Pole, as they are equivalent to existing
    same-country-code zones for post-1970 timestamps.  The data entries for
    these names are unchanged, so the names continue to work as before.

  Changes affecting code internals

    zic -c now runs way faster on 64-bit hosts when given large numbers.

    zic now uses vfprintf to avoid allocating and freeing some memory.

    tzselect now computes the list of continents from the data,
    rather than have it hard-coded.

    Minor changes pacify GCC 4.7.3 and GCC 4.8.1.

  Changes affecting the build procedure

    The 'leapseconds' file is now generated automatically from a
    new file 'leap-seconds.list', which is a copy of
    <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
    A new source file 'leapseconds.awk' implements this.
    The goal is simplification of the future maintenance of 'leapseconds'.

    When building the 'posix' or 'right' subdirectories, if the
    subdirectory would be a copy of the default subdirectory, it is
    now made a symbolic link if that is supported.  This saves about
    2 MB of file system space.

    The links America/Shiprock and Antarctica/South_Pole have been
    moved to the 'backward' file.  This affects only nondefault builds
    that omit 'backward'.

  Changes affecting version-control only

    .gitignore now ignores 'date'.

  Changes affecting documentation and commentary

    Changes to the 'tzfile' man page

      It now mentions that the binary file format may be extended in
      future versions by appending data.

      It now refers to the 'zdump' and 'zic' man pages.

    Changes to the 'zic' man page

      It lists conditions that elicit a warning with '-v'.

      It says that the behavior is unspecified when duplicate names
      are given, or if the source of one link is the target of another.

      Its examples are updated to match the latest data.

      The definition of white space has been clarified slightly.
      (Thanks to Michael Deckers.)

    Changes to the 'Theory' file

      There is a new section about the accuracy of the tz database,
      describing the many ways that errors can creep in, and
      explaining why so many of the pre-1970 timestamps are wrong or
      misleading (thanks to Steve Allen, Lester Caine, and Garrett
      Wollman for discussions that contributed to this).

      The 'Theory' file describes LMT better (this follows a
      suggestion by Guy Harris).

      It refers to the 2013 edition of POSIX rather than the 2004 edition.

      It's mentioned that excluding 'backward' should not affect the
      other data, and it suggests at least one zone.tab name per
      inhabited country (thanks to Stephen Colebourne).

      Some longstanding restrictions on names are documented, e.g.,
      'America/New_York' precludes 'America/New_York/Bronx'.

      It gives more reasons for the 1970 cutoff.

      It now mentions which time_t variants are supported, such as
      signed integer time_t.  (Thanks to Paul Goyette for reporting
      typos in an experimental version of this change.)

      (Thanks to Philip Newton for correcting typos in these changes.)

    Documentation and commentary is more careful to distinguish UT in
    general from UTC in particular.  (Thanks to Steve Allen.)

    Add a better source for the Zurich 1894 transition.
    (Thanks to Pierre-Yves Berger.)

    Update shapefile citations in tz-link.htm.  (Thanks to Guy Harris.)


Release 2013d - 2013-07-05 07:38:01 -0700

  Changes affecting future timestamps:

    Morocco's midsummer transitions this year are July 7 and August 10,
    not July 9 and August 8.  (Thanks to Andrew Paprocki.)

    Israel now falls back on the last Sunday of October.
    (Thanks to Ephraim Silverberg.)

  Changes affecting past timestamps:

    Specify Jerusalem's location more precisely; this changes the pre-1880
    times by 2 s.

  Changing affecting metadata only:

    Fix typos in the entries for country codes BQ and SX.

  Changes affecting code:

    Rework the code to fix a bug with handling Australia/Macquarie on
    32-bit hosts (thanks to Arthur David Olson).

    Port to platforms like NetBSD, where time_t can be wider than long.

    Add support for testing time_t types other than the system's.
    Run 'make check_time_t_alternatives' to try this out.
    Currently, the tests fail for unsigned time_t;
    this should get fixed at some point.

  Changes affecting documentation and commentary:

    Deemphasize the significance of national borders.

    Update the zdump man page.

    Remove obsolete NOID comment (thanks to Denis Excoffier).

    Update several URLs and comments in the web pages.

    Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).

    Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).


Release 2013c - 2013-04-19 16:17:40 -0700

  Changes affecting current and future timestamps:

    Palestine observed DST starting March 29, 2013.  (Thanks to
    Steffen Thorsen.)  From 2013 on, Gaza and Hebron both observe DST,
    with the predicted rules being the last Thursday in March at 24:00
    to the first Friday on or after September 21 at 01:00.

    Assume that the recent change to Paraguay's DST rules is permanent,
    by moving the end of DST to the 4th Sunday in March every year.
    (Thanks to Carlos Raúl Perasso.)

  Changes affecting past timestamps:

    Fix some historical data for Palestine to agree with that of
    timeanddate.com, as follows:

	  The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
	  00:00 Apr 1.

	  The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
	  02:00.

	  The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.

	  The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.

	  The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.

	  The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.

    Fix times of habitation for Macquarie to agree with the Tasmania
    Parks & Wildlife Service history, which indicates that permanent
    habitation was 1899-1919 and 1948 on.

  Changing affecting metadata only:

    Macquarie Island is politically part of Australia, not Antarctica.
    (Thanks to Tobias Conradi.)

    Sort Macquarie more-consistently with other parts of Australia.
    (Thanks to Tim Parenti.)


Release 2013b - 2013-03-10 22:33:40 -0700

  Changes affecting current and future timestamps:

    Haiti uses US daylight-saving rules this year, and presumably future years.
    This changes timestamps starting today.  (Thanks to Steffen Thorsen.)

    Paraguay will end DST on March 24 this year.
    (Thanks to Steffen Thorsen.)  For now, assume it's just this year.

    Morocco does not observe DST during Ramadan;
    try to predict Ramadan in Morocco as best we can.
    (Thanks to Erik Homoet for the heads-up.)

  Changes affecting commentary:

    Update URLs in tz-link page.  Add URLs for webOS, BB10, iOS.
    Update URL for Solaris.  Mention Internet RFC 6557.
    Update Internet RFCs 2445->5545, 2822->5322.
    Switch from FTP to HTTP for Internet RFCs.


Release 2013a - 2013-02-27 09:20:35 -0800

  Change affecting binary data format:

    The zone offset at the end of version-2-format zone files is now
    allowed to be 24:00, as per POSIX.1-2008.  (Thanks to Arthur David Olson.)

  Changes affecting current and future timestamps:

    Chile's 2013 rules, and we guess rules for 2014 and later, will be
    the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
    (Thanks to Steffen Thorsen and Robert Elz.)

    New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
    (Thanks to Tobias Conradi and Arthur David Olson.)

  Many changes affect historical timestamps before 1940.
  These were deduced from: Milne J. Civil time. Geogr J. 1899
  Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.

  Changes affecting the code:

    Fix zic bug that mishandled Egypt's 2010 changes (this also affected
    the data).  (Thanks to Arthur David Olson.)

    Fix localtime bug when time_t is unsigned and data files were generated
    by a signed time_t system.  (Thanks to Doug Bailey for reporting and
    to Arthur David Olson for fixing.)

    Allow the email address for bug reports to be set by the packager.
    The default is tz@iana.org, as before.  (Thanks to Joseph S. Myers.)

    Update HTML checking to be compatible with Ubuntu 12.10.

    Check that files are a safe subset of ASCII.  At some point we may
    relax this requirement to a safe subset of UTF-8.  Without the
    check, some non-UTF-8 encodings were leaking into the distribution.

  Commentary changes:

    Restore a comment about copyright notices that was inadvertently deleted.
    (Thanks to Arthur David Olson.)

    Improve the commentary about which districts observe what times
    in Russia.  (Thanks to Oscar van Vlijmen and Arthur David Olson.)

    Add web page links to tz.js.

    Add "Run by the Monkeys" to tz-art.  (Thanks to Arthur David Olson.)


Release 2012j - 2012-11-12 18:34:49 -0800

  Libya moved to CET this weekend, but with DST planned next year.
  (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)

  Signatures now have the extension .asc, not .sign, as that's more
  standard.  (Thanks to Phil Pennock.)

  The output of 'zdump --version', and of 'zic --version', now
  uses a format that is more typical for --version.
  (Thanks to Joseph S. Myers.)

  The output of 'tzselect --help', 'zdump --help', and 'zic --help'
  now uses tz@iana.org rather than the old elsie address.

  zic -v now complains about abbreviations that are less than 3
  or more than 6 characters, as per Posix.  Formerly, it checked
  for abbreviations that were more than 3.

  'make public' no longer puts its temporary directory under /tmp,
  and uses the just-built zic rather than the system zic.

  Various fixes to documentation and commentary.


Release 2012i - 2012-11-03 12:57:09 -0700

  Cuba switches from DST tomorrow at 01:00.  (Thanks to Steffen Thorsen.)

  Linker flags can now be specified via LDFLAGS.
  AWK now defaults to 'awk', not 'nawk'.
  The shell in tzselect now defaults to /bin/bash, but this can
  be overridden by specifying KSHELL.
  The main web page now mentions the unofficial GitHub repository.
  (Thanks to Mike Frysinger.)

  Tarball signatures can now be built by running 'make signatures'.
  There are also new makefile rules 'tarballs', 'check_public', and
  separate makefile rules for each tarball and signature file.
  A few makefile rules are now more portable to strict POSIX.

  The main web page now lists the canonical IANA URL.


Release 2012h - 2012-10-26 22:49:10 -0700

  Bahia no longer has DST.  (Thanks to Kelley Cook.)

  Tocantins has DST.  (Thanks to Rodrigo Severo.)

  Israel has new DST rules next year.  (Thanks to Ephraim Silverberg.)

  Jordan stays on DST this winter.  (Thanks to Steffen Thorsen.)

  Web page updates.

  More C modernization, except that at Arthur David Olson's suggestion
  the instances of 'register' were kept.


Release 2012g - 2012-10-17 20:59:45 -0700

  Samoa fall 2012 and later.  (Thanks to Nicholas Pereira and Robert Elz.)

  Palestine fall 2012.  (Thanks to Steffen Thorsen.)

  Assume C89.

  To attack the version-number problem, this release ships the file
  'Makefile' (which contains the release number) in both the tzcode and
  the tzdata tarballs.  The two Makefiles are identical, and should be
  identical in any matching pair of tarballs, so it shouldn't matter
  which order you extract the tarballs.  Perhaps we can come up with a
  better version-number scheme at some point; this scheme does have the
  virtue of not adding more files.


Release 2012f - 2012-09-12 23:17:03 -0700

  * australasia (Pacific/Fiji): Fiji DST is October 21 through January
    20 this year.  (Thanks to Steffen Thorsen.)


Release 2012e - 2012-08-02 20:44:55 -0700

  * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
    (Thanks to Steffen Thorsen.)

  * Use a single version number for both code and data.

  * .gitignore: New file.

  * Remove trailing white space.


Release code2012c-data2012d - 2012-07-19 16:35:33 -0700

  Changes for Morocco's timestamps, which take effect in a couple of
  hours, along with infrastructure changes to accommodate how the tz
  code and data are released on IANA.


Release data2012c - 2012-03-27 12:17:25 -0400

  africa
	Summer time changes for Morocco (to start late April 2012)

  asia
	Changes for 2012 for Gaza & the West Bank (Hebron) and Syria

  northamerica
	Haiti following US/Canada rules for 2012 (and we're assuming,
	for now anyway, for the future).


Release 2012b - 2012-03-02 12:29:15 +0700

  There is just one change to tzcode2012b (compared with 2012a):
  the Makefile that was accidentally included with 2012a has been
  replaced with the version that should have been there, which is
  identical with the previous version (from tzcode2011i).

  There are just two changes in tzdata2012b compared with 2012a.

  Most significantly, summer time in Cuba has been delayed 3 weeks
  (now starts April 1 rather than March 11).   Since Mar 11 (the old start
  date, as listed in 2012a) is just a little over a week away, this
  change is urgent.

  Less importantly, an excess tab in one of the changes in zone.tab
  in 2012a has been removed.


Release 2012a - 2012-03-01 18:28:10 +0700

  The changes in tzcode2012a (compared to the previous version, 2011i)
  are entirely to the README and tz-art.htm and tz-link.htm files, if
  none of those concern you, you can ignore the code update.  The changes
  reflect the changed addresses for the mailing list and the code and
  data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
  has been added to tz-link.htm).

  In tzdata2012a (compared to the previous release, which was 2011n)
  the major changes are:
	Chile 2011/2012 and 2012/2013 summer time date adjustments.
	Falkland Islands onto permanent summer time (we're assuming for the
		foreseeable future, though 2012 is all we're fairly certain of.)
	Armenia has abolished Summer Time.
	Tokelau jumped the International Date Line back last December
		(just the same as their near neighbour, Samoa).
	America/Creston is a new zone for a small area of British Columbia
	There will be a leapsecond 2012-06-30 23:59:60 UTC.

  Other minor changes are:
	Corrections to 1918 Canadian summer time end dates.
	Updated URL for UK time zone history (in comments)
	A few typos in Le Corre's list of free French place names (comments)


Release data2011n - 2011-10-30 14:57:54 +0700

  There are three changes of note - most urgently, Cuba (America/Havana)
  has extended summer time by two weeks, now to end on Nov 13, rather than
  the (already past) Oct 30.   Second, the Pridnestrovian Moldavian Republic
  (Europe/Tiraspol) decided not to split from the rest of Moldova after
  all, and consequently that zone has been removed (again) and reinstated
  in the "backward" file as a link to Europe/Chisinau.   And third, the
  end date for Fiji's summer time this summer was moved forward from the
  earlier planned Feb 26, to Jan 22.

  Apart from that, Moldova (MD) returns to a single entry in zone.tab
  (and the incorrect syntax that was in the 2011m version of that file
  is so fixed - it would have been fixed in a different way had this
  change not happened - that's the "missing" sccs version id).


Release data2011m - 2011-10-24 21:42:16 +0700

  In particular, the typos in comments in the data (2011-11-17 should have
  been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
  Tim Parenti noted) have been fixed, and the change for Ukraine has been
  made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
  Tim Parenti, and also Denys Gavrysh)

  In addition, I added Europe/Tiraspol to zone.tab.

  This time, all the files have new version numbers...  (including the files
  otherwise unchanged in 2011m that were changed in 2011l but didn't get new
  version numbers there...)


Release data2011l - 2011-10-10 11:15:43 +0700

  There are just 2 changes that cause different generated tzdata files from
  zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
  is included, but commented out.  Compared with the diff I sent out last week,
  this version also includes attributions for the sources for the changes
  (in much the same format as ado used, but the html tags have not been
  checked, verified, or used in any way at all, so if there are errors there,
  please let me know.)


Release data2011k - 2011-09-20 17:54:03 -0400

  [not summarized]


Release data2011j - 2011-09-12 09:22:49 -0400

  (contemporary changes for Samoa; past changes for Kenya, Uganda, and
  Tanzania); there are also two spelling corrections to comments in
  the australasia file (with thanks to Christos Zoulas).


Release 2011i - 2011-08-29 05:56:32 -0400

  [not summarized]


Release data2011h - 2011-06-15 18:41:48 -0400

  Russia and Curaçao changes


Release 2011g - 2011-04-25 09:07:22 -0400

  update the rules for Egypt to reflect its abandonment of DST this year


Release 2011f - 2011-04-06 17:14:53 -0400

  [not summarized]


Release 2011e - 2011-03-31 16:04:38 -0400

  Morocco, Chile, and tz-link changes


Release 2011d - 2011-03-14 09:18:01 -0400

  changes that impact present-day timestamps in Cuba, Samoa, and Turkey


Release 2011c - 2011-03-07 09:30:09 -0500

  These do affect current timestamps in Chile and Annette Island, Canada.


Release 2011b - 2011-02-07 08:44:50 -0500

  [not summarized]


Release 2011a - 2011-01-24 10:30:16 -0500

  [not summarized]


Release data2010o - 2010-11-01 09:18:23 -0400

  change to the end of DST in Fiji in 2011


Release 2010n - 2010-10-25 08:19:17 -0400

  [not summarized]


Release 2010m - 2010-09-27 09:24:48 -0400

  Hong Kong, Vostok, and zic.c changes


Release 2010l - 2010-08-16 06:57:25 -0400

  [not summarized]


Release 2010k - 2010-07-26 10:42:27 -0400

  [not summarized]


Release 2010j - 2010-05-10 09:07:48 -0400

  changes for Bahía de Banderas and for version naming


Release data2010i - 2010-04-16 18:50:45 -0400

  the end of DST in Morocco on 2010-08-08


Release data2010h - 2010-04-05 09:58:56 -0400

  [not summarized]


Release data2010g - 2010-03-24 11:14:53 -0400

  [not summarized]


Release 2010f - 2010-03-22 09:45:46 -0400

  [not summarized]


Release data2010e - 2010-03-08 14:24:27 -0500

  corrects the Dhaka bug found by Danvin Ruangchan


Release data2010d - 2010-03-06 07:26:01 -0500

  [not summarized]


Release 2010c - 2010-03-01 09:20:58 -0500

  changes including KRE's suggestion for earlier initialization of
  "goahead" and "goback" structure elements


Release code2010a - 2010-02-16 10:40:04 -0500

  [not summarized]


Release data2010b - 2010-01-20 12:37:01 -0500

  Mexico changes


Release data2010a - 2010-01-18 08:30:04 -0500

  changes to Dhaka


Release data2009u - 2009-12-26 08:32:28 -0500

  changes to DST in Bangladesh


Release 2009t - 2009-12-21 13:24:27 -0500

  [not summarized]


Release data2009s - 2009-11-14 10:26:32 -0500

  (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change


Release 2009r - 2009-11-09 10:10:31 -0500

  "antarctica" and "tz-link.htm" changes


Release 2009q - 2009-11-02 09:12:40 -0500

  with two corrections as reported by Eric Muller and Philip Newton


Release data2009p - 2009-10-23 15:05:27 -0400

  Argentina (including San Luis) changes (with the correction from
  Mariano Absatz)


Release data2009o - 2009-10-14 16:49:38 -0400

  Samoa (commentary only), Pakistan, and Bangladesh changes


Release data2009n - 2009-09-22 15:13:38 -0400

  added commentary for Argentina and a change to the end of DST in
  2009 in Pakistan


Release data2009m - 2009-09-03 10:23:43 -0400

  Samoa and Palestine changes


Release data2009l - 2009-08-14 09:13:07 -0400

  Samoa (comments only) and Egypt


Release 2009k - 2009-07-20 09:46:08 -0400

  [not summarized]


Release data2009j - 2009-06-15 06:43:59 -0400

  Bangladesh change (with a short turnaround since the DST change is
  impending)


Release 2009i - 2009-06-08 09:21:22 -0400

  updating for DST in Bangladesh this year


Release 2009h - 2009-05-26 09:19:14 -0400

  [not summarized]


Release data2009g - 2009-04-20 16:34:07 -0400

  Cairo


Release data2009f - 2009-04-10 11:00:52 -0400

  correct DST in Pakistan


Release 2009e - 2009-04-06 09:08:11 -0400

  [not summarized]


Release 2009d - 2009-03-23 09:38:12 -0400

  Morocco, Tunisia, Argentina, and American Astronomical Society changes


Release data2009c - 2009-03-16 09:47:51 -0400

  change to the start of Cuban DST


Release 2009b - 2009-02-09 11:15:22 -0500

  [not summarized]


Release 2009a - 2009-01-21 10:09:39 -0500

  [not summarized]


Release data2008i - 2008-10-21 12:10:25 -0400

  southamerica and zone.tab files, with Argentina DST rule changes and
  United States zone reordering and recommenting


Release 2008h - 2008-10-13 07:33:56 -0400

  [not summarized]


Release 2008g - 2008-10-06 09:03:18 -0400

  Fix a broken HTML anchor and update Brazil's DST transitions;
  there's also a slight reordering of information in tz-art.htm.


Release data2008f - 2008-09-09 22:33:26 -0400

  [not summarized]


Release 2008e - 2008-07-28 14:11:17 -0400

  changes by Arthur David Olson and Jesper Nørgaard Welen


Release data2008d - 2008-07-07 09:51:38 -0400

  changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo


Release data2008c - 2008-05-19 17:48:03 -0400

  Pakistan, Morocco, and Mongolia


Release data2008b - 2008-03-24 08:30:59 -0400

  including renaming Asia/Calcutta to Asia/Kolkata, with a backward
  link provided


Release 2008a - 2008-03-08 05:42:16 -0500

  [not summarized]


Release 2007k - 2007-12-31 10:25:22 -0500

  most importantly, changes to the "southamerica" file based on
  Argentina's readoption of daylight saving time


Release 2007j - 2007-12-03 09:51:01 -0500

  1. eliminate the "P" (parameter) macro;

  2. the "noncontroversial" changes circulated on the time zone
  mailing list (less the changes to "logwtmp.c");

  3. eliminate "too many transition" errors when "min" is used in time
  zone rules;

  4. changes by Paul Eggert (including updated information for Venezuela).


Release data2007i - 2007-10-30 10:28:11 -0400

  changes for Cuba and Syria


Release 2007h - 2007-10-01 10:05:51 -0400

  changes by Paul Eggert, as well as an updated link to the ICU
  project in tz-link.htm


Release 2007g - 2007-08-20 10:47:59 -0400

  changes by Paul Eggert

  The "leapseconds" file has been updated to incorporate the most
  recent International Earth Rotation and Reference Systems Service
  (IERS) bulletin.

  There's an addition to tz-art.htm regarding the television show "Medium".


Release 2007f - 2007-05-07 10:46:46 -0400

  changes by Paul Eggert (including Haiti, Turks and Caicos, and New
  Zealand)

  changes to zic.c to allow hour values greater than 24 (along with
  Paul's improved time value overflow checking)


Release 2007e - 2007-04-02 10:11:52 -0400

  Syria and Honduras changes by Paul Eggert

  zic.c variable renaming changes by Arthur David Olson


Release 2007d - 2007-03-20 08:48:30 -0400

  changes by Paul Eggert

  the elimination of white space at the ends of lines


Release 2007c - 2007-02-26 09:09:37 -0500

  changes by Paul Eggert


Release 2007b - 2007-02-12 09:34:20 -0500

  Paul Eggert's proposed change to the quotation handling logic in zic.c.

  changes to the commentary in "leapseconds" reflecting the IERS
  announcement that there is to be no positive leap second at the end
  of June 2007.


Release 2007a - 2007-01-08 12:28:29 -0500

  changes by Paul Eggert

  Derick Rethan's Asmara change

  Oscar van Vlijmen's Easter Island local mean time change

  symbolic link changes


Release 2006p - 2006-11-27 08:54:27 -0500

  changes by Paul Eggert


Release 2006o - 2006-11-06 09:18:07 -0500

  changes by Paul Eggert


Release 2006n - 2006-10-10 11:32:06 -0400

  changes by Paul Eggert


Release 2006m - 2006-10-02 15:32:35 -0400

  changes for Uruguay, Palestine, and Egypt by Paul Eggert

  (minimalist) changes to zic.8 to clarify "until" information


Release data2006l - 2006-09-18 12:58:11 -0400

  Paul's best-effort work on this coming weekend's Egypt time change


Release 2006k - 2006-08-28 12:19:09 -0400

  changes by Paul Eggert


Release 2006j - 2006-08-21 09:56:32 -0400

  changes by Paul Eggert


Release code2006i - 2006-08-07 12:30:55 -0400

  localtime.c fixes

  Ken Pizzini's conversion script


Release code2006h - 2006-07-24 09:19:37 -0400

  adds public domain notices to four files

  includes a fix for transition times being off by a second

  adds a new recording to the "arts" file (information courtesy Colin Bowern)


Release 2006g - 2006-05-08 17:18:09 -0400

  northamerica changes by Paul Eggert


Release 2006f - 2006-05-01 11:46:00 -0400

  a missing version number problem is fixed (with thanks to Bradley
  White for catching the problem)


Release 2006d - 2006-04-17 14:33:43 -0400

  changes by Paul Eggert

  added new items to tz-arts.htm that were found by Paul


Release 2006c - 2006-04-03 10:09:32 -0400

  two sets of data changes by Paul Eggert

  a fencepost error fix in zic.c

  changes to zic.c and the "europe" file to minimize differences
  between output produced by the old 32-bit zic and the new 64-bit
  version


Release 2006b - 2006-02-20 10:08:18 -0500
  [tz32code2006b + tz64code2006b + tzdata2006b]

  64-bit code

  All SCCS IDs were bumped to "8.1" for this release.


Release 2006a - 2006-01-30 08:59:31 -0500

  changes by Paul Eggert (in particular, Indiana time zone moves)

  an addition to the zic manual page to describe how special-case
  transitions are handled


Release 2005r - 2005-12-27 09:27:13 -0500

  Canadian changes by Paul Eggert

  They also add "<pre>" directives to time zone data files and reflect
  changes to warning message logic in "zdump.c" (but with calls to
  "gettext" kept unbundled at the suggestion of Ken Pizzini).


Release 2005q - 2005-12-13 09:17:09 -0500

  Nothing earth-shaking here:
	1.  Electronic mail addresses have been removed.
	2.  Casts of the return value of exit have been removed.
	3.  Casts of the argument of is.* macros have been added.
	4.  Indentation in one section of zic.c has been fixed.
	5.  References to dead URLs in the data files have been dealt with.


Release 2005p - 2005-12-05 10:30:53 -0500

  "systemv", "tz-link.htm", and "zdump.c" changes
  (less the casts of arguments to the is* macros)


Release 2005o - 2005-11-28 10:55:26 -0500

  Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert

  zdump.c lint fixes by Arthur David Olson


Release 2005n - 2005-10-03 09:44:09 -0400

  changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
  et al. changes)


Release 2005m - 2005-08-29 12:15:40 -0400

  changes by Paul Eggert (with a small tweak to the tz-art change)

  a declaration of an unused variable has been removed from zdump.c


Release 2005l - 2005-08-22 12:06:39 -0400

  changes by Paul Eggert

  overflow/underflow checks by Arthur David Olson, minus changes to
  the "Theory" file about the pending addition of 64-bit data (I grow
  less confident of the changes being accepted with each passing day,
  and the changes no longer increase the data files nine-fold--there's
  less than a doubling in size by my local Sun's reckoning)


Release 2005k - 2005-07-14 14:14:24 -0400

  The "leapseconds" file has been edited to reflect the recently
  announced leap second at the end of 2005.

  I've also deleted electronic mail addresses from the files as an
  anti-spam measure.


Release 2005j - 2005-06-13 14:34:13 -0400

  These reflect changes to limit the length of time zone abbreviations
  and the characters used in those abbreviations.

  There are also changes to handle POSIX-style "quoted" timezone
  environment variables.

  The changes were circulated on the time zone mailing list; the only
  change since then was the removal of a couple of minimum-length of
  abbreviation checks.


Release data2005i - 2005-04-21 15:04:16 -0400

  changes (most importantly to Nicaragua and Haiti) by Paul Eggert


Release 2005h - 2005-04-04 11:24:47 -0400

  changes by Paul Eggert

  minor changes to Makefile and zdump.c to produce more useful output
  when doing a "make typecheck"


Release 2005g - 2005-03-14 10:11:21 -0500

  changes by Paul Eggert (a change to current DST rules in Uruguay and
  an update to a link to time zone software)


Release 2005f - 2005-03-01 08:45:32 -0500

  data and documentation changes by Paul Eggert


Release 2005e - 2005-02-10 15:59:44 -0500

  [not summarized]


Release code2005d - 2005-01-31 09:21:47 -0500

  make zic complain about links to links if the -v flag is used

  have "make public" do more code checking

  add an include to "localtime.c" for the benefit of gcc systems


Release 2005c - 2005-01-17 18:36:29 -0500

  get better results when mktime runs on a system where time_t is double

  changes to the data files (most importantly to Paraguay)


Release 2005b - 2005-01-10 09:19:54 -0500

  Get localtime and gmtime working on systems with exotic time_t types.

  Update the leap second commentary in the "leapseconds" file.


Release 2005a - 2005-01-01 13:13:44 -0500

  [not summarized]


Release code2004i - 2004-12-14 13:42:58 -0500

  Deal with systems where time_t is unsigned.


Release code2004h - 2004-12-07 11:40:18 -0500

  64-bit-time_t changes


Release 2004g - 2004-11-02 09:06:01 -0500

  update to Cuba (taking effect this weekend)

  other changes by Paul Eggert

  correction of the spelling of Oslo

  changed versions of difftime.c and private.h


Release code2004f - 2004-10-21 10:25:22 -0400

  Cope with wide-ranging tm_year values.


Release 2004e - 2004-10-11 14:47:21 -0400

  Brazil/Argentina/Israel changes by Paul Eggert

  changes to tz-link.htm by Paul

  one small fix to Makefile


Release 2004d - 2004-09-22 08:27:29 -0400

  Avoid overflow problems when TM_YEAR_BASE is added to an integer.


Release 2004c - 2004-08-11 12:06:26 -0400

  asctime-related changes

  (variants of) some of the documentation changes suggested by Paul Eggert


Release 2004b - 2004-07-19 14:33:35 -0400

  data changes by Paul Eggert - most importantly, updates for Argentina


Release 2004a - 2004-05-27 12:00:47 -0400

  changes by Paul Eggert

  Handle DST transitions that occur at the end of a month in some
  years but at the start of the following month in other years.

  Add a copy of the correspondence that's the basis for claims about
  DST in the Navajo Nation.


Release 2003e - 2003-12-15 09:36:47 -0500

  changes by Arthur David Olson (primarily code changes)

  changes by Paul Eggert (primarily data changes)

  minor changes to "Makefile" and "northamerica" (in the latter case,
  optimization of the "Toronto" rules)


Release 2003d - 2003-10-06 09:34:44 -0400

  changes by Paul Eggert


Release 2003c - 2003-09-16 10:47:05 -0400

  Fix bad returns in zic.c's inleap function.
  Thanks to Bradley White for catching the problem!


Release 2003b - 2003-09-16 07:13:44 -0400

  Add a "--version" option (and documentation) to the zic and zdump commands.

  changes to overflow/underflow checking in zic

  a localtime typo fix.

  Update the leapseconds and tz-art.htm files.


Release 2003a - 2003-03-24 09:30:54 -0500

  changes by Paul Eggert

  a few additions and modifications to the tz-art.htm file


Release 2002d - 2002-10-15 13:12:42 -0400

  changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab

  There's also a new time zone quote in "tz-art.htm".


Release 2002c - 2002-04-04 11:55:20 -0500

  changes by Paul Eggert

  Change zic.c to avoid creating symlinks to files that don't exist.


Release 2002b - 2002-01-28 12:56:03 -0500

  [These change notes are for Release 2002a, which was corrupted.
  2002b was a corrected version of 2002a.]

  changes by Paul Eggert

  Update the "leapseconds" file to note that there'll be no leap
  second at the end of June, 2002.

  Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.

  Change to "difftime.c" to avoid sizeof problems.


Release 2001d - 2001-10-09 13:31:32 -0400

  changes by Paul Eggert


Release 2001c - 2001-06-05 13:59:55 -0400

  changes by Paul Eggert and Andrew Brown


Release 2001b - 2001-04-05 16:44:38 -0400

  changes by Paul Eggert (modulo jnorgard's typo fix)

  tz-art.htm has been HTMLified.


Release 2001a - 2001-03-13 12:57:44 -0500

  changes by Paul Eggert

  An addition to the "leapseconds" file: comments with the text of the
  latest IERS leap second notice.

  Trailing white space has been removed from data file lines, and
  repeated spaces in "Rule Jordan" lines in the "asia" file have been
  converted to tabs.


Release 2000h - 2000-12-14 15:33:38 -0500

  changes by Paul Eggert

  one typo fix in the "art" file

  With providence, this is the last update of the millennium.


Release 2000g - 2000-10-10 11:35:22 -0400

  changes by Paul Eggert

  correction of John Mackin's name submitted by Robert Elz

  Garry Shandling's Daylight Saving Time joke (!?!) from the recent
  Emmy Awards broadcast.


Release 2000f - 2000-08-10 09:31:58 -0400

  changes by Paul Eggert

  Added information in "tz-art.htm" on a Seinfeld reference to DST.

  Error checking and messages in the "yearistype" script have been
  improved.


Release 2000e - 2000-07-31 09:27:54 -0400

  data changes by Paul Eggert

  a change to the default value of the defined constant HAVE_STRERROR

  the addition of a Dave Barry quote on DST to the tz-arts file


Release 2000d - 2000-04-20 15:43:04 -0400

  changes to the documentation and code of strftime for C99 conformance

  a bug fix for date.c

  These are based on (though modified from) changes by Paul Eggert.


Release 2000c - 2000-03-04 10:31:43 -0500

  changes by Paul Eggert


Release 2000b - 2000-02-21 12:16:29 -0500

  changes by Paul Eggert and Joseph Myers

  modest tweaks to the tz-art.htm and tz-link.htm files


Release 2000a - 2000-01-18 09:21:26 -0500

  changes by Paul Eggert

  The two hypertext documents have also been renamed.


Release code1999i-data1999j - 1999-11-15 18:43:22 -0500

  Paul Eggert's changes

  additions to the "zic" manual page and the "Arts.htm" file


Release code1999h-data1999i - 1999-11-08 14:55:21 -0500

  [not summarized]


Release data1999h - 1999-10-07 03:50:29 -0400

  changes by Paul Eggert to "europe" (most importantly, fixing
  Lithuania and Estonia)


Release 1999g - 1999-09-28 11:06:18 -0400

  data changes by Paul Eggert (most importantly, the change for
  Lebanon that buys correctness for this coming Sunday)

  The "code" file contains changes to "Makefile" and "checktab.awk" to
  allow better checking of time zone files before they are published.


Release 1999f - 1999-09-23 09:48:14 -0400

  changes by Arthur David Olson and Paul Eggert


Release 1999e - 1999-08-17 15:20:54 -0400

  changes circulated by Paul Eggert, although the change to handling
  of DST-specifying timezone names has been commented out for now
  (search for "XXX" in "localtime.c" for details).  These files also
  do not make any changes to the start of DST in Brazil.

  In addition to Paul's changes, there are updates to "Arts.htm" and
  cleanups of URLs.


Release 1999d - 1999-03-30 11:31:07 -0500

  changes by Paul Eggert

  The Makefile's "make public" rule has also been changed to do a test
  compile of each individual time zone data file (which should help
  avoid problems such as the one we had with Nicosia).


Release 1999c - 1999-03-25 09:47:47 -0500

  changes by Paul Eggert, most importantly the change for Chile.


Release 1999b - 1999-02-01 17:51:44 -0500

  changes by Paul Eggert

  code changes (suggested by Mani Varadarajan, mani at be.com) for
  correct handling of symbolic links when building using a relative directory

  code changes to generate correct messages for failed links

  updates to the URLs in Arts.htm


Release 1999a - 1999-01-19 16:20:29 -0500

  error message internationalizations and corrections in zic.c and
  zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
  to whom thanks!)


Release code1998h-data1998i - 1998-10-01 09:56:10 -0400

  changes for Brazil, Chile, and Germany

  support for use of "24:00" in the input files for the time zone compiler


Release code1998g-data1998h - 1998-09-24 10:50:28 -0400

  changes by Paul Eggert

  correction to a define in the "private.h" file


Release data1998g - 1998-08-11 03:28:35 -0000
  [tzdata1998g.tar.gz is missing!]

  Lithuanian change provided by mgedmin at pub.osf.it

  Move creation of the GMT link with Etc/GMT to "etcetera" (from
  "backward") to ensure that the GMT file is created even where folks
  don't want the "backward" links (as suggested by Paul Eggert).


Release data1998f - 1998-07-20 13:50:00 -0000
  [tzdata1998f.tar.gz is missing!]

  Update the "leapseconds" file to include the newly-announced
  insertion at the end of 1998.


Release code1998f - 1998-06-01 10:18:31 -0400

  addition to localtime.c by Guy Harris


Release 1998e - 1998-05-28 09:56:26 -0400

  The Makefile is changed to produce zoneinfo-posix rather than
  zoneinfo/posix, and to produce zoneinfo-leaps rather than
  zoneinfo/right.

  data changes by Paul Eggert

  changes from Guy Harris to provide asctime_r and ctime_r

  A usno1998 file (substantially identical to usno1997) has been added.


Release 1998d - 1998-05-14 11:58:34 -0400

  changes to comments (in particular, elimination of references to CIA maps).
  "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
  where changes occur.


Release 1998c - 1998-02-28 12:32:26 -0500

  changes by Paul Eggert (save the "French correction," on which I'll
  wait for the dust to settle)

  symlink changes

  changes and additions to Arts.htm


Release 1998b - 1998-01-17 14:31:51 -0500

  URL cleanups and additions


Release 1998a - 1998-01-13 12:37:35 -0500

  changes by Paul Eggert


Release code1997i-data1997k - 1997-12-29 09:53:41 -0500

  changes by Paul Eggert, with minor modifications from Arthur David
  Olson to make the files more browser friendly


Release code1997h-data1997j - 1997-12-18 17:47:35 -0500

  minor changes to put "TZif" at the start of each timezone information file

  a rule has also been added to the Makefile so you can
	make zones
  to just recompile the zone information files (rather than doing a
  full "make install" with its other effects).


Release data1997i - 1997-10-07 08:45:38 -0400

  changes to Africa by Paul Eggert


Release code1997g-data1997h - 1997-09-04 16:56:54 -0400

  corrections for Uruguay (and other locations)

  Arthur David Olson's simple-minded fix allowing mktime to both
  correctly handle leap seconds and correctly handle tm_sec values
  upon which arithmetic has been performed.


Release code1997f-data1997g - 1997-07-19 13:15:02 -0400

  Paul Eggert's updates

  a small change to a function prototype;

  "Music" has been renamed "Arts.htm", HTMLified, and augmented to
  include information on Around the World in Eighty Days.


Release code1997e-data1997f - 1997-05-03 18:52:34 -0400

  fixes to zic's error handling

  changes inspired by the item circulated on Slovenia

  The description of Web resources has been HTMLified for browsing
  convenience.

  A new piece of tz-related music has been added to the "Music" file.


Release code1997d-data1997e - 1997-03-29 12:48:52 -0500

  Paul Eggert's latest suggestions


Release code1997c-data1997d - 1997-03-07 20:37:54 -0500

  changes to "zic.c" to correct performance of the "-s" option

  a new file "usno1997"


Release data1997c - 1997-03-04 09:58:18 -0500

  changes in Israel


Release 1997b - 1997-02-27 18:34:19 -0500

  The data file incorporates the 1997 leap second.

  The code file incorporates Arthur David Olson's take on the
  zic/multiprocessor/directory-creation situation.


Release 1997a - 1997-01-21 09:11:10 -0500

  Paul Eggert's Antarctica (and other changes)

  Arthur David Olson finessed the "getopt" issue by checking against
  both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
  is returned while SunOS 5.5's manual says EOF is returned).


Release code1996o-data1996n - 1996-12-27 21:42:05 -0500

  Paul Eggert's latest changes


Release code1996n - 1996-12-16 09:42:02 -0500

  link snapping fix from Bruce Evans (via Garrett Wollman)


Release data1996m - 1996-11-24 02:37:34 -0000
  [tzdata1996m.tar.gz is missing!]

  Paul Eggert's batch of changes


Release code1996m-data1996l - 1996-11-05 14:00:12 -0500

  No functional changes here; the files have simply been changed to
  make more use of ISO style dates in comments. The names of the above
  files now include the year in full.


Release code96l - 1996-09-08 17:12:20 -0400

  tzcode96k was missing a couple of pieces.


Release 96k - 1996-09-08 16:06:22 -0400

  the latest round of changes from Paul Eggert

  the recent Year 2000 material


Release code96j - 1996-07-30 13:18:53 -0400

  Set sp->typecnt as suggested by Timothy Patrick Murphy.


Release code96i - 1996-07-27 20:11:35 -0400

  Paul's suggested patch for strftime %V week numbers


Release data96i - 1996-07-01 18:13:04 -0400

  "northamerica" and "europe" changes by Paul Eggert


Release code96h - 1996-06-05 08:02:21 -0400

  fix for handling transitions specified in Universal Time

  Some "public domain" notices have also been added.


Release code96g - 1996-05-16 14:00:26 -0400

  fix for the simultaneous-DST-and-zone-change challenge


Release data96h - 1996-05-09 17:40:51 -0400

  changes by Paul Eggert


Release code96f-data96g - 1996-05-03 03:09:59 -0000
  [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]

  The changes get us some of the way to fixing the problems noted in Paul
  Eggert's letter yesterday (in addition to a few others).  The approach
  has been to make zic a bit smarter about figuring out what time zone
  abbreviations apply just after the time specified in the "UNTIL" part
  of a zone line.  Putting the smarts in zic means avoiding having
  transition times show up in both "Zone" lines and "Rule" lines, which
  in turn avoids multiple transition time entries in time zone files.
  (This also makes the zic input files such as "europe" a bit shorter and
  should ease maintenance.)


Release data96f - 1996-04-19 19:20:03 -0000
  [tzdata96f.tar.gz is missing!]

  The only changes are to the "northamerica" file; the time zone
  abbreviation for Denver is corrected to MST (and MDT), and the
  comments for Mexico have been updated.


Release data96e - 1996-03-19 17:37:26 -0500

  Proposals by Paul Eggert, in particular the Portugal change that
  comes into play at the end of this month.


Release data96d - 1996-03-18 20:49:39 -0500

  [not summarized]


Release code96e - 1996-02-29 15:43:27 -0000
  [tzcode96e.tar.gz is missing!]

  internationalization changes and the fix to the documentation for strftime


Release code96d-data96c - 1996-02-12 11:05:27 -0500

  The "code" file simply updates Bob Kridle's electronic address.

  The "data" file updates rules for Mexico.


Release data96b - 1996-01-27 15:44:42 -0500

  Kiribati change


Release code96c - 1996-01-16 16:58:15 -0500

  leap-year streamlining and binary-search changes

  fix to newctime.3


Release code96b - 1996-01-10 20:42:39 -0500

  fixes and enhancements from Paul Eggert, including code that
  emulates the behavior of recent versions of the SunOS "date"
  command.


Release 96a - 1996-01-06 09:08:24 -0500

  Israel updates

  fixes to strftime.c for correct ISO 8601 week number generation,
  plus support for two new formats ('G' and 'g') to give ISO 8601 year
  numbers (which are not necessarily the same as calendar year numbers)


Release code95i-data95m - 1995-12-21 12:46:47 -0500

  The latest revisions from Paul Eggert are included, the usno1995
  file has been updated, and a new file ("WWW") covering useful URLs
  has been added.


Release code95h-data95l - 1995-12-19 18:10:12 -0500

  A simplification of a macro definition, a change to data for Sudan,
  and (for last minute shoppers) notes in the "Music" file on the CD
  "Old Man Time".


Release code95g-data95k - 1995-10-30 10:32:47 -0500

  (slightly reformatted) 8-bit-clean proposed patch

  minor patch: US/Eastern -> America/New_York

  snapshot of the USNO's latest data ("usno1995")

  some other minor cleanups


Release code95f-data95j - 1995-10-28 21:01:34 -0000
  [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]

  European cleanups

  support for 64-bit time_t's

  optimization in localtime.c


Release code95e - 1995-10-13 13:23:57 -0400

  the mktime change to scan from future to past when trying to find time zone
  offsets


Release data95i - 1995-09-26 10:43:26 -0400

  For Canada/Central, guess that the Sun customer's "one week too
  early" was just a approximation, and the true error is one month
  too early.  This is consistent with the rest of Canada.


Release data95h - 1995-09-21 11:26:48 -0400

  latest changes from Paul Eggert


Release code95d - 1995-09-14 11:14:45 -0400

  the addition of a "Music" file, which documents four recorded
  versions of the tune "Save That Time".


Release data95g - 1995-09-01 17:21:36 -0400

  "yearistype" correction


Release data95f - 1995-08-28 20:46:56 -0400

  Paul Eggert's change to the australasia file


Release data95e - 1995-07-08 18:02:34 -0400

  The only change is a leap second at the end of this year.
  Thanks to Bradley White for forwarding news on the leap second.


Release data95d - 1995-07-03 13:26:22 -0400

  Paul Eggert's changes


Release data95c - 1995-07-02 19:19:28 -0400

  changes to "asia", "backward", "europe", and "southamerica"
  (read: northamericacentrics need not apply)


Release code95c - 1995-03-13 14:00:46 -0500

  one-line fix for sign extension problems in detzcode


Release 95b - 1995-03-04 11:22:38 -0500

  Minor changes in both:

  The "code" file contains a workaround for the lack of "unistd.h" in
  Microsoft C++ version 7.

  The "data" file contains a fixed "Link" for America/Shiprock.


Release 94h - 1994-12-10 12:51:14 -0500

  The files:

  *	incorporate the changes to "zdump" and "date" to make changes to
	the "TZ" environment variable permanent;

  *	incorporate the table changes by Paul Eggert;

  *	include (and document) support for universal time specifications in
	data files - but do not (yet) include use of this feature in the
	data files.

  Think of this as "TZ Classic" - the software has been set up not to break if
  universal time shows up in its input, and data entries have been
  left as is so as not to break existing implementations.


Release data94f - 1994-08-20 12:56:09 -0400

  (with thanks!) the latest data updates from Paul Eggert


Release data94e - 1994-06-04 13:13:53 -0400

  [not summarized]


Release code94g - 1994-05-05 12:14:07 -0400

  fix missing "optind.c" and a reference to it in the Makefile


Release code94f - 1994-05-05 13:00:33 -0000
  [tzcode94f.tar.gz is missing!]

  changes to avoid overflow in difftime, as well as changes to cope
  with the 52/53 challenge in strftime


Release code94e - 1994-03-30 23:32:59 -0500

  change for the benefit of PCTS


Release 94d - 1994-02-24 15:42:25 -0500

  Avoid clashes with POSIX semantics for zones such as GMT+4.

  Some other very minor housekeeping is also present.


Release code94c - 1994-02-10 08:52:40 -0500

  Fix bug where mkdirs was broken unless you compile with
  -fwritable-strings (which is generally losing to do).


Release 94b - 1994-02-07 10:04:33 -0500

  work by Paul Eggert who notes:

  I found another book of time zone histories by E W Whitman; it's not
  as extensive as Shanks but has a few goodies of its own.  I used it
  to update the tables.  I also fixed some more as a result of
  correspondence with Adam David and Peter Ilieve, and move some stray
  links from 'europe' to 'backward'.  I corrected some scanning errors
  in usno1989.

  As far as the code goes, I fixed zic to allow years in the range
  INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
  And I cleaned up the zic documentation a little bit.


Release data94a - 1994-02-03 08:58:54 -0500

  It simply incorporates the recently announced leap second into the
  "leapseconds" file.


Release 93g - 1993-11-22 17:28:27 -0500

  Paul Eggert has provided a good deal of historic information (based
  on Shanks), and there are some code changes to deal with the buglets
  that crawled out in dealing with the new information.


Release 93f - 1993-10-15 12:27:46 -0400

  Paul Eggert's changes


Release 93e - 1993-09-05 21:21:44 -0400

  This has updated data for Israel, England, and Kwajalein.  There's
  also an update to "zdump" to cope with Kwajalein's 24-hour jump.
  Thanks to Paul Eggert and Peter Ilieve for the changes.


Release 93d - 1993-06-17 23:34:17 -0400

  new fix and new data on Israel


Release 93c - 1993-06-06 19:31:55 -0400

  [not summarized]


Release 93b - 1993-02-02 14:53:58 -0500

  updated "leapseconds" file


Release 93 - 1993-01-08 07:01:06 -0500

  At kre's suggestion, the package has been split in two - a code piece
  (which also includes documentation) that's only of use to folks who
  want to recompile things and a data piece useful to anyone who can
  run "zic".

  The new version has a few changes to the data files, a few
  portability changes, and an off-by-one fix (with thanks to
  Tom Karzes at deshaw.com for providing a description and a
  solution).


Release 92c - 1992-11-21 17:35:36 -0000
  [tz92c.tar.Z is missing!]

  The fallout from the latest round of DST transitions.

  There are changes for Portugal, Saskatchewan, and "Pacific-New";
  there's also a change to "zic.c" that makes it portable to more systems.


Release 92 - 1992-04-25 18:17:03 -0000
  [tz92.tar.Z is missing!]

  By popular demand (well, at any rate, following a request by kre at munnari)


The 1989 update of the time zone package featured:

  *	POSIXization (including interpretation of POSIX-style TZ environment
	variables, provided by Guy Harris),
  *	ANSIfication (including versions of "mktime" and "difftime"),
  *	SVIDulation (an "altzone" variable)
  *	MACHination (the "gtime" function)
  *	corrections to some time zone data (including corrections to the rules
	for Great Britain and New Zealand)
  *	reference data from the United States Naval Observatory for folks who
	want to do additional time zones
  *	and the 1989 data for Saudi Arabia.

  (Since this code will be treated as "part of the implementation" in some
  places and as "part of the application" in others, there's no good way to
  name functions, such as timegm, that are not part of the proposed ANSI C
  standard; such functions have kept their old, underscore-free names in this
  update.)

  And the "dysize" function has disappeared; it was present to allow
  compilation of the "date" command on old BSD systems, and a version of "date"
  is now provided in the package.  The "date" command is not created when you
  "make all" since it may lack options provided by the version distributed with
  your operating system, or may not interact with the system in the same way
  the native version does.

  Since POSIX frowns on correct leap second handling, the default behavior of
  the "zic" command (in the absence of a "-L" option) has been changed to omit
  leap second information from its output files.


-----
Notes

This file contains copies of the part of each release announcement
that talks about the changes in that release.  The text has been
adapted and reformatted for the purposes of this file.

Traditionally a release R consists of a pair of tarball files,
tzcodeR.tar.gz and tzdataR.tar.gz.  However, some releases (e.g.,
code2010a, data2012c) consist of just one or the other tarball, and a
few (e.g., code2012c-data2012d) have tarballs with mixed version
numbers.  Recent releases also come in an experimental format
consisting of a single tarball tzdb-R.tar.lz with extra data.

Release timestamps are taken from the release's commit (for newer,
Git-based releases), from the newest file in the tarball (for older
releases, where this info is available) or from the email announcing
the release (if all else fails; these are marked with a time zone
abbreviation of -0000 and an "is missing!" comment).

Earlier versions of the code and data were not announced on the tz
list and are not summarized here.

This file is in the public domain.

Local Variables:
coding: utf-8
End: