# tzdb data for Australasia and environs, and for much of the Pacific
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file also includes Pacific islands.
# Notes are at the end of this file
###############################################################################
# Australia
# Please see the notes below for the controversy about "EST" versus "AEST" etc.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Aus 1917 only - Jan 1 0:01 1:00 D
Rule Aus 1917 only - Mar 25 2:00 0 S
Rule Aus 1942 only - Jan 1 2:00 1:00 D
Rule Aus 1942 only - Mar 29 2:00 0 S
Rule Aus 1942 only - Sep 27 2:00 1:00 D
Rule Aus 1943 1944 - Mar lastSun 2:00 0 S
Rule Aus 1943 only - Oct 3 2:00 1:00 D
# Go with Whitman and the Australian National Standards Commission, which
# says W Australia didn't use DST in 1943/1944. Ignore Whitman's claim that
# 1944/1945 was just like 1943/1944.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Northern Territory
Zone Australia/Darwin 8:43:20 - LMT 1895 Feb
9:00 - ACST 1899 May
9:30 Aus AC%sT
# Western Australia
#
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AW 1974 only - Oct lastSun 2:00s 1:00 D
Rule AW 1975 only - Mar Sun>=1 2:00s 0 S
Rule AW 1983 only - Oct lastSun 2:00s 1:00 D
Rule AW 1984 only - Mar Sun>=1 2:00s 0 S
Rule AW 1991 only - Nov 17 2:00s 1:00 D
Rule AW 1992 only - Mar Sun>=1 2:00s 0 S
Rule AW 2006 only - Dec 3 2:00s 1:00 D
Rule AW 2007 2009 - Mar lastSun 2:00s 0 S
Rule AW 2007 2008 - Oct lastSun 2:00s 1:00 D
Zone Australia/Perth 7:43:24 - LMT 1895 Dec
8:00 Aus AW%sT 1943 Jul
8:00 AW AW%sT
Zone Australia/Eucla 8:35:28 - LMT 1895 Dec
8:45 Aus +0845/+0945 1943 Jul
8:45 AW +0845/+0945
# Queensland
#
# From Alex Livingston (1996-11-01):
# I have heard or read more than once that some resort islands off the coast
# of Queensland chose to keep observing daylight-saving time even after
# Queensland ceased to.
#
# From Paul Eggert (1996-11-22):
# IATA SSIM (1993-02/1994-09) say that the Holiday Islands (Hayman, Lindeman,
# Hamilton) observed DST for two years after the rest of Queensland stopped.
# Hamilton is the largest, but there is also a Hamilton in Victoria,
# so use Lindeman.
#
# From J William Piggott (2016-02-20):
# There is no location named Holiday Islands in Queensland Australia; holiday
# islands is a colloquial term used globally. Hayman and Lindeman are at the
# north and south extremes of the Whitsunday Islands archipelago, and
# Hamilton is in between; it is reasonable to believe that this time zone
# applies to all of the Whitsundays.
# http://www.australia.gov.au/about-australia/australian-story/austn-islands
#
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AQ 1971 only - Oct lastSun 2:00s 1:00 D
Rule AQ 1972 only - Feb lastSun 2:00s 0 S
Rule AQ 1989 1991 - Oct lastSun 2:00s 1:00 D
Rule AQ 1990 1992 - Mar Sun>=1 2:00s 0 S
Rule Holiday 1992 1993 - Oct lastSun 2:00s 1:00 D
Rule Holiday 1993 1994 - Mar Sun>=1 2:00s 0 S
Zone Australia/Brisbane 10:12:08 - LMT 1895
10:00 Aus AE%sT 1971
10:00 AQ AE%sT
Zone Australia/Lindeman 9:55:56 - LMT 1895
10:00 Aus AE%sT 1971
10:00 AQ AE%sT 1992 Jul
10:00 Holiday AE%sT
# South Australia
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AS 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AS 1986 only - Oct 19 2:00s 1:00 D
Rule AS 1987 2007 - Oct lastSun 2:00s 1:00 D
Rule AS 1972 only - Feb 27 2:00s 0 S
Rule AS 1973 1985 - Mar Sun>=1 2:00s 0 S
Rule AS 1986 1990 - Mar Sun>=15 2:00s 0 S
Rule AS 1991 only - Mar 3 2:00s 0 S
Rule AS 1992 only - Mar 22 2:00s 0 S
Rule AS 1993 only - Mar 7 2:00s 0 S
Rule AS 1994 only - Mar 20 2:00s 0 S
Rule AS 1995 2005 - Mar lastSun 2:00s 0 S
Rule AS 2006 only - Apr 2 2:00s 0 S
Rule AS 2007 only - Mar lastSun 2:00s 0 S
Rule AS 2008 max - Apr Sun>=1 2:00s 0 S
Rule AS 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Adelaide 9:14:20 - LMT 1895 Feb
9:00 - ACST 1899 May
9:30 Aus AC%sT 1971
9:30 AS AC%sT
# Tasmania
#
# From Paul Eggert (2005-08-16):
# http://www.bom.gov.au/climate/averages/tables/dst_times.shtml
# says King Island didn't observe DST from WWII until late 1971.
#
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AT 1967 only - Oct Sun>=1 2:00s 1:00 D
Rule AT 1968 only - Mar lastSun 2:00s 0 S
Rule AT 1968 1985 - Oct lastSun 2:00s 1:00 D
Rule AT 1969 1971 - Mar Sun>=8 2:00s 0 S
Rule AT 1972 only - Feb lastSun 2:00s 0 S
Rule AT 1973 1981 - Mar Sun>=1 2:00s 0 S
Rule AT 1982 1983 - Mar lastSun 2:00s 0 S
Rule AT 1984 1986 - Mar Sun>=1 2:00s 0 S
Rule AT 1986 only - Oct Sun>=15 2:00s 1:00 D
Rule AT 1987 1990 - Mar Sun>=15 2:00s 0 S
Rule AT 1987 only - Oct Sun>=22 2:00s 1:00 D
Rule AT 1988 1990 - Oct lastSun 2:00s 1:00 D
Rule AT 1991 1999 - Oct Sun>=1 2:00s 1:00 D
Rule AT 1991 2005 - Mar lastSun 2:00s 0 S
Rule AT 2000 only - Aug lastSun 2:00s 1:00 D
Rule AT 2001 max - Oct Sun>=1 2:00s 1:00 D
Rule AT 2006 only - Apr Sun>=1 2:00s 0 S
Rule AT 2007 only - Mar lastSun 2:00s 0 S
Rule AT 2008 max - Apr Sun>=1 2:00s 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Hobart 9:49:16 - LMT 1895 Sep
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1967
10:00 AT AE%sT
Zone Australia/Currie 9:35:28 - LMT 1895 Sep
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1971 Jul
10:00 AT AE%sT
# Victoria
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AV 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AV 1972 only - Feb lastSun 2:00s 0 S
Rule AV 1973 1985 - Mar Sun>=1 2:00s 0 S
Rule AV 1986 1990 - Mar Sun>=15 2:00s 0 S
Rule AV 1986 1987 - Oct Sun>=15 2:00s 1:00 D
Rule AV 1988 1999 - Oct lastSun 2:00s 1:00 D
Rule AV 1991 1994 - Mar Sun>=1 2:00s 0 S
Rule AV 1995 2005 - Mar lastSun 2:00s 0 S
Rule AV 2000 only - Aug lastSun 2:00s 1:00 D
Rule AV 2001 2007 - Oct lastSun 2:00s 1:00 D
Rule AV 2006 only - Apr Sun>=1 2:00s 0 S
Rule AV 2007 only - Mar lastSun 2:00s 0 S
Rule AV 2008 max - Apr Sun>=1 2:00s 0 S
Rule AV 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Melbourne 9:39:52 - LMT 1895 Feb
10:00 Aus AE%sT 1971
10:00 AV AE%sT
# New South Wales
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule AN 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AN 1972 only - Feb 27 2:00s 0 S
Rule AN 1973 1981 - Mar Sun>=1 2:00s 0 S
Rule AN 1982 only - Apr Sun>=1 2:00s 0 S
Rule AN 1983 1985 - Mar Sun>=1 2:00s 0 S
Rule AN 1986 1989 - Mar Sun>=15 2:00s 0 S
Rule AN 1986 only - Oct 19 2:00s 1:00 D
Rule AN 1987 1999 - Oct lastSun 2:00s 1:00 D
Rule AN 1990 1995 - Mar Sun>=1 2:00s 0 S
Rule AN 1996 2005 - Mar lastSun 2:00s 0 S
Rule AN 2000 only - Aug lastSun 2:00s 1:00 D
Rule AN 2001 2007 - Oct lastSun 2:00s 1:00 D
Rule AN 2006 only - Apr Sun>=1 2:00s 0 S
Rule AN 2007 only - Mar lastSun 2:00s 0 S
Rule AN 2008 max - Apr Sun>=1 2:00s 0 S
Rule AN 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Sydney 10:04:52 - LMT 1895 Feb
10:00 Aus AE%sT 1971
10:00 AN AE%sT
Zone Australia/Broken_Hill 9:25:48 - LMT 1895 Feb
10:00 - AEST 1896 Aug 23
9:00 - ACST 1899 May
9:30 Aus AC%sT 1971
9:30 AN AC%sT 2000
9:30 AS AC%sT
# Lord Howe Island
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule LH 1981 1984 - Oct lastSun 2:00 1:00 -
Rule LH 1982 1985 - Mar Sun>=1 2:00 0 -
Rule LH 1985 only - Oct lastSun 2:00 0:30 -
Rule LH 1986 1989 - Mar Sun>=15 2:00 0 -
Rule LH 1986 only - Oct 19 2:00 0:30 -
Rule LH 1987 1999 - Oct lastSun 2:00 0:30 -
Rule LH 1990 1995 - Mar Sun>=1 2:00 0 -
Rule LH 1996 2005 - Mar lastSun 2:00 0 -
Rule LH 2000 only - Aug lastSun 2:00 0:30 -
Rule LH 2001 2007 - Oct lastSun 2:00 0:30 -
Rule LH 2006 only - Apr Sun>=1 2:00 0 -
Rule LH 2007 only - Mar lastSun 2:00 0 -
Rule LH 2008 max - Apr Sun>=1 2:00 0 -
Rule LH 2008 max - Oct Sun>=1 2:00 0:30 -
Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb
10:00 - AEST 1981 Mar
10:30 LH +1030/+1130 1985 Jul
10:30 LH +1030/+11
# Australian miscellany
#
# Ashmore Is, Cartier
# no indigenous inhabitants; only seasonal caretakers
# no times are set
#
# Coral Sea Is
# no indigenous inhabitants; only meteorologists
# no times are set
#
# Macquarie
# Permanent occupation (scientific station) 1911-1915 and since 25 March 1948;
# sealing and penguin oil station operated Nov 1899 to Apr 1919. See the
# Tasmania Parks & Wildlife Service history of sealing at Macquarie Island
# http://www.parks.tas.gov.au/index.aspx?base=1828
# http://www.parks.tas.gov.au/index.aspx?base=1831
# Guess that it was like Australia/Hobart while inhabited before 2010.
#
# From Steffen Thorsen (2010-03-10):
# We got these changes from the Australian Antarctic Division:
# - Macquarie Island will stay on UTC+11 for winter and therefore not
# switch back from daylight savings time when other parts of Australia do
# on 4 April.
#
# From Arthur David Olson (2013-05-23):
# The 1919 transition is overspecified below so pre-2013 zics
# will produce a binary file with an [A]EST-type as the first 32-bit type;
# this is required for correct handling of times before 1916 by
# pre-2013 versions of localtime.
Zone Antarctica/Macquarie 0 - -00 1899 Nov
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1919 Apr 1 0:00s
0 - -00 1948 Mar 25
10:00 Aus AE%sT 1967
10:00 AT AE%sT 2010
10:00 1:00 AEDT 2011
10:00 AT AE%sT
# Christmas
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Christmas 7:02:52 - LMT 1895 Feb
7:00 - +07
# Cocos (Keeling) Is
# These islands were ruled by the Ross family from about 1830 to 1978.
# We don't know when standard time was introduced; for now, we guess 1900.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Cocos 6:27:40 - LMT 1900
6:30 - +0630
# Fiji
# Milne gives 11:55:44 for Suva.
# From Alexander Krivenyshev (2009-11-10):
# According to Fiji Broadcasting Corporation, Fiji plans to re-introduce DST
# from November 29th 2009 to April 25th 2010.
#
# "Daylight savings to commence this month"
# http://www.radiofiji.com.fj/fullstory.php?id=23719
# http://www.worldtimezone.com/dst_news/dst_news_fiji01.html
# From Steffen Thorsen (2009-11-10):
# The Fiji Government has posted some more details about the approved
# amendments:
# http://www.fiji.gov.fj/publish/page_16198.shtml
# From Steffen Thorsen (2010-03-03):
# The Cabinet in Fiji has decided to end DST about a month early, on
# 2010-03-28 at 03:00.
# The plan is to observe DST again, from 2010-10-24 to sometime in March
# 2011 (last Sunday a good guess?).
#
# Official source:
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=1096:3310-cabinet-approves-change-in-daylight-savings-dates&catid=49:cabinet-releases&Itemid=166
#
# A bit more background info here:
# https://www.timeanddate.com/news/time/fiji-dst-ends-march-2010.html
# From Alexander Krivenyshev (2010-10-24):
# According to Radio Fiji and Fiji Times online, Fiji will end DST 3
# weeks earlier than expected - on March 6, 2011, not March 27, 2011...
# Here is confirmation from Government of the Republic of the Fiji Islands,
# Ministry of Information (fiji.gov.fj) web site:
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=2608:daylight-savings&catid=71:press-releases&Itemid=155
# http://www.worldtimezone.com/dst_news/dst_news_fiji04.html
# From Steffen Thorsen (2011-10-03):
# Now the dates have been confirmed, and at least our start date
# assumption was correct (end date was one week wrong).
#
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=4966:daylight-saving-starts-in-fiji&catid=71:press-releases&Itemid=155
# which says
# Members of the public are reminded to change their time to one hour in
# advance at 2am to 3am on October 23, 2011 and one hour back at 3am to
# 2am on February 26 next year.
# From Ken Rylander (2011-10-24)
# Another change to the Fiji DST end date. In the TZ database the end date for
# Fiji DST 2012, is currently Feb 26. This has been changed to Jan 22.
#
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=5017:amendments-to-daylight-savings&catid=71:press-releases&Itemid=155
# states:
#
# The end of daylight saving scheduled initially for the 26th of February 2012
# has been brought forward to the 22nd of January 2012.
# The commencement of daylight saving will remain unchanged and start
# on the 23rd of October, 2011.
# From the Fiji Government Online Portal (2012-08-21) via Steffen Thorsen:
# The Minister for Labour, Industrial Relations and Employment Mr Jone Usamate
# today confirmed that Fiji will start daylight savings at 2 am on Sunday 21st
# October 2012 and end at 3 am on Sunday 20th January 2013.
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=6702&catid=71&Itemid=155
# From the Fijian Government Media Center (2013-08-30) via David Wheeler:
# Fiji will start daylight savings on Sunday 27th October, 2013 ...
# move clocks forward by one hour from 2am
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-SUNDAY,-27th-OCTOBER-201.aspx
# From Steffen Thorsen (2013-01-10):
# Fiji will end DST on 2014-01-19 02:00:
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVINGS-TO-END-THIS-MONTH-%281%29.aspx
# From Ken Rylander (2014-10-20):
# DST will start Nov. 2 this year.
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-SUNDAY,-NOVEMBER-2ND.aspx
# From a government order dated 2015-08-26 and published as Legal Notice No. 77
# in the Government of Fiji Gazette Supplement No. 24 (2015-08-28),
# via Ken Rylander (2015-09-02):
# the daylight saving period is 1 hour in advance of the standard time
# commencing at 2.00 am on Sunday 1st November, 2015 and ending at
# 3.00 am on Sunday 17th January, 2016.
# From Raymond Kumar (2016-10-04):
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-6th-NOVEMBER,-2016.aspx
# "Fiji's daylight savings will begin on Sunday, 6 November 2016, when
# clocks go forward an hour at 2am to 3am.... Daylight Saving will
# end at 3.00am on Sunday 15th January 2017."
# From Paul Eggert (2017-08-21):
# Dominic Fok writes (2017-08-20) that DST ends 2018-01-14, citing
# Extraordinary Government of Fiji Gazette Supplement No. 21 (2017-08-27),
# [Legal Notice No. 41] of an order of the previous day by J Usamate.
# From Raymond Kumar (2018-07-13):
# http://www.fijitimes.com/government-approves-2018-daylight-saving/
# ... The daylight saving period will end at 3am on Sunday January 13, 2019.
# From Paul Eggert (2019-08-06):
# Today Raymond Kumar reported the Government of Fiji Gazette Supplement No. 27
# (2019-08-02) said that Fiji observes DST "commencing at 2.00 am on
# Sunday, 10 November 2019 and ending at 3.00 am on Sunday, 12 January 2020."
# For now, guess DST from 02:00 the second Sunday in November to 03:00
# the first Sunday on or after January 12. January transitions reportedly
# depend on when school terms start. Although the guess is ad hoc, it matches
# transitions planned this year and seems more likely to match future practice
# than guessing no DST.
# From Michael Deckers (2019-08-06):
# https://www.laws.gov.fj/LawsAsMade/downloadfile/848
# From Raymond Kumar (2020-10-08):
# [DST in Fiji] is from December 20th 2020, till 17th January 2021.
# From Alan Mintz (2020-10-08):
# https://www.laws.gov.fj/LawsAsMade/GetFile/1071
# From Tim Parenti (2020-10-08):
# https://www.fijivillage.com/news/Daylight-saving-from-Dec-20th-this-year-to-Jan-17th-2021-8rf4x5/
# "Minister for Employment, Parveen Bala says they had never thought of
# stopping daylight saving. He says it was just to decide on when it should
# start and end. Bala says it is a short period..."
# Since the end date is still in line with our ongoing predictions, assume for
# now that the later-than-usual start date is a one-time departure from the
# recent second Sunday in November pattern.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Fiji 1998 1999 - Nov Sun>=1 2:00 1:00 -
Rule Fiji 1999 2000 - Feb lastSun 3:00 0 -
Rule Fiji 2009 only - Nov 29 2:00 1:00 -
Rule Fiji 2010 only - Mar lastSun 3:00 0 -
Rule Fiji 2010 2013 - Oct Sun>=21 2:00 1:00 -
Rule Fiji 2011 only - Mar Sun>=1 3:00 0 -
Rule Fiji 2012 2013 - Jan Sun>=18 3:00 0 -
Rule Fiji 2014 only - Jan Sun>=18 2:00 0 -
Rule Fiji 2014 2018 - Nov Sun>=1 2:00 1:00 -
Rule Fiji 2015 max - Jan Sun>=12 3:00 0 -
Rule Fiji 2019 only - Nov Sun>=8 2:00 1:00 -
Rule Fiji 2020 only - Dec 20 2:00 1:00 -
Rule Fiji 2021 max - Nov Sun>=8 2:00 1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Fiji 11:55:44 - LMT 1915 Oct 26 # Suva
12:00 Fiji +12/+13
# French Polynesia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Gambier -8:59:48 - LMT 1912 Oct # Rikitea
-9:00 - -09
Zone Pacific/Marquesas -9:18:00 - LMT 1912 Oct
-9:30 - -0930
Zone Pacific/Tahiti -9:58:16 - LMT 1912 Oct # Papeete
-10:00 - -10
# Clipperton (near North America) is administered from French Polynesia;
# it is uninhabited.
# Guam
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
# http://guamlegislature.com/Public_Laws_5th/PL05-025.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-59-7-Guam-Daylight-Savings-Time-May-6-1959.pdf
Rule Guam 1959 only - Jun 27 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-61-5-Revocation-of-Daylight-Saving-Time-and-Restoratio.pdf
Rule Guam 1961 only - Jan 29 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-67-13-Guam-Daylight-Savings-Time.pdf
Rule Guam 1967 only - Sep 1 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-69-2-Repeal-of-Guam-Daylight-Saving-Time.pdf
Rule Guam 1969 only - Jan 26 0:01 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-69-10-Guam-Daylight-Saving-Time.pdf
Rule Guam 1969 only - Jun 22 2:00 1:00 D
Rule Guam 1969 only - Aug 31 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-70-10-Guam-Daylight-Saving-Time.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-70-30-End-of-Guam-Daylight-Saving-Time.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-71-5-Guam-Daylight-Savings-Time.pdf
Rule Guam 1970 1971 - Apr lastSun 2:00 1:00 D
Rule Guam 1970 1971 - Sep Sun>=1 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-73-28.-Guam-Day-light-Saving-Time.pdf
Rule Guam 1973 only - Dec 16 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-74-7-Guam-Daylight-Savings-Time-Rescinded.pdf
Rule Guam 1974 only - Feb 24 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-76-13-Daylight-Savings-Time.pdf
Rule Guam 1976 only - May 26 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-76-25-Revocation-of-E.O.-76-13.pdf
Rule Guam 1976 only - Aug 22 2:01 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-77-4-Daylight-Savings-Time.pdf
Rule Guam 1977 only - Apr 24 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-77-18-Guam-Standard-Time.pdf
Rule Guam 1977 only - Aug 28 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Guam -14:21:00 - LMT 1844 Dec 31
9:39:00 - LMT 1901 # Agana
10:00 - GST 1941 Dec 10 # Guam
9:00 - +09 1944 Jul 31
10:00 Guam G%sT 2000 Dec 23
10:00 - ChST # Chamorro Standard Time
Link Pacific/Guam Pacific/Saipan # N Mariana Is
# Kiribati
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tarawa 11:32:04 - LMT 1901 # Bairiki
12:00 - +12
Zone Pacific/Enderbury -11:24:20 - LMT 1901
-12:00 - -12 1979 Oct
-11:00 - -11 1994 Dec 31
13:00 - +13
Zone Pacific/Kiritimati -10:29:20 - LMT 1901
-10:40 - -1040 1979 Oct
-10:00 - -10 1994 Dec 31
14:00 - +14
# N Mariana Is
# See Pacific/Guam.
# Marshall Is
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Majuro 11:24:48 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1944 Jan 30
11:00 - +11 1969 Oct
12:00 - +12
Zone Pacific/Kwajalein 11:09:20 - LMT 1901
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1944 Feb 6
11:00 - +11 1969 Oct
-12:00 - -12 1993 Aug 20 24:00
12:00 - +12
# Micronesia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Chuuk -13:52:52 - LMT 1844 Dec 31
10:07:08 - LMT 1901
10:00 - +10 1914 Oct
9:00 - +09 1919 Feb 1
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
10:00 - +10
Zone Pacific/Pohnpei -13:27:08 - LMT 1844 Dec 31 # Kolonia
10:32:52 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
11:00 - +11
Zone Pacific/Kosrae -13:08:04 - LMT 1844 Dec 31
10:51:56 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
11:00 - +11 1969 Oct
12:00 - +12 1999
11:00 - +11
# Nauru
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Nauru 11:07:40 - LMT 1921 Jan 15 # Uaobe
11:30 - +1130 1942 Aug 29
9:00 - +09 1945 Sep 8
11:30 - +1130 1979 Feb 10 2:00
12:00 - +12
# New Caledonia
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule NC 1977 1978 - Dec Sun>=1 0:00 1:00 -
Rule NC 1978 1979 - Feb 27 0:00 0 -
Rule NC 1996 only - Dec 1 2:00s 1:00 -
# Shanks & Pottenger say the following was at 2:00; go with IATA.
Rule NC 1997 only - Mar 2 2:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Noumea 11:05:48 - LMT 1912 Jan 13 # Nouméa
11:00 NC +11/+12
###############################################################################
# New Zealand
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule NZ 1927 only - Nov 6 2:00 1:00 S
Rule NZ 1928 only - Mar 4 2:00 0 M
Rule NZ 1928 1933 - Oct Sun>=8 2:00 0:30 S
Rule NZ 1929 1933 - Mar Sun>=15 2:00 0 M
Rule NZ 1934 1940 - Apr lastSun 2:00 0 M
Rule NZ 1934 1940 - Sep lastSun 2:00 0:30 S
Rule NZ 1946 only - Jan 1 0:00 0 S
# Since 1957 Chatham has been 45 minutes ahead of NZ, but until 2018a
# there was no documented single notation for the date and time of this
# transition. Duplicate the Rule lines for now, to give the 2018a change
# time to percolate out.
Rule NZ 1974 only - Nov Sun>=1 2:00s 1:00 D
Rule Chatham 1974 only - Nov Sun>=1 2:45s 1:00 -
Rule NZ 1975 only - Feb lastSun 2:00s 0 S
Rule Chatham 1975 only - Feb lastSun 2:45s 0 -
Rule NZ 1975 1988 - Oct lastSun 2:00s 1:00 D
Rule Chatham 1975 1988 - Oct lastSun 2:45s 1:00 -
Rule NZ 1976 1989 - Mar Sun>=1 2:00s 0 S
Rule Chatham 1976 1989 - Mar Sun>=1 2:45s 0 -
Rule NZ 1989 only - Oct Sun>=8 2:00s 1:00 D
Rule Chatham 1989 only - Oct Sun>=8 2:45s 1:00 -
Rule NZ 1990 2006 - Oct Sun>=1 2:00s 1:00 D
Rule Chatham 1990 2006 - Oct Sun>=1 2:45s 1:00 -
Rule NZ 1990 2007 - Mar Sun>=15 2:00s 0 S
Rule Chatham 1990 2007 - Mar Sun>=15 2:45s 0 -
Rule NZ 2007 max - Sep lastSun 2:00s 1:00 D
Rule Chatham 2007 max - Sep lastSun 2:45s 1:00 -
Rule NZ 2008 max - Apr Sun>=1 2:00s 0 S
Rule Chatham 2008 max - Apr Sun>=1 2:45s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Auckland 11:39:04 - LMT 1868 Nov 2
11:30 NZ NZ%sT 1946 Jan 1
12:00 NZ NZ%sT
Zone Pacific/Chatham 12:13:48 - LMT 1868 Nov 2
12:15 - +1215 1946 Jan 1
12:45 Chatham +1245/+1345
Link Pacific/Auckland Antarctica/McMurdo
# Auckland Is
# uninhabited; Māori and Moriori, colonial settlers, pastoralists, sealers,
# and scientific personnel have wintered
# Campbell I
# minor whaling stations operated 1909/1914
# scientific station operated 1941/1995;
# previously whalers, sealers, pastoralists, and scientific personnel wintered
# was probably like Pacific/Auckland
# Cook Is
# From Shanks & Pottenger:
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Cook 1978 only - Nov 12 0:00 0:30 -
Rule Cook 1979 1991 - Mar Sun>=1 0:00 0 -
Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua
-10:30 - -1030 1978 Nov 12
-10:00 Cook -10/-0930
###############################################################################
# Niue
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Niue -11:19:40 - LMT 1901 # Alofi
-11:20 - -1120 1951
-11:30 - -1130 1978 Oct 1
-11:00 - -11
# Norfolk
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Norfolk 11:11:52 - LMT 1901 # Kingston
11:12 - +1112 1951
11:30 - +1130 1974 Oct 27 02:00s
11:30 1:00 +1230 1975 Mar 2 02:00s
11:30 - +1130 2015 Oct 4 02:00s
11:00 - +11 2019 Jul
11:00 AN +11/+12
# Palau (Belau)
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Palau -15:02:04 - LMT 1844 Dec 31 # Koror
8:57:56 - LMT 1901
9:00 - +09
# Papua New Guinea
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Port_Moresby 9:48:40 - LMT 1880
9:48:32 - PMMT 1895 # Port Moresby Mean Time
10:00 - +10
#
# From Paul Eggert (2014-10-13):
# Base the Bougainville entry on the Arawa-Kieta region, which appears to have
# the most people even though it was devastated in the Bougainville Civil War.
#
# Although Shanks gives 1942-03-15 / 1943-11-01 for UT +09, these dates
# are apparently rough guesswork from the starts of military campaigns.
# The World War II entries below are instead based on Arawa-Kieta.
# The Japanese occupied Kieta in July 1942,
# according to the Pacific War Online Encyclopedia
# https://pwencycl.kgbudge.com/B/o/Bougainville.htm
# and seem to have controlled it until their 1945-08-21 surrender.
#
# The Autonomous Region of Bougainville switched from UT +10 to +11
# on 2014-12-28 at 02:00. They call +11 "Bougainville Standard Time".
# See:
# http://www.bougainville24.com/bougainville-issues/bougainville-gets-own-timezone/
#
Zone Pacific/Bougainville 10:22:16 - LMT 1880
9:48:32 - PMMT 1895
10:00 - +10 1942 Jul
9:00 - +09 1945 Aug 21
10:00 - +10 2014 Dec 28 2:00
11:00 - +11
# Pitcairn
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Pitcairn -8:40:20 - LMT 1901 # Adamstown
-8:30 - -0830 1998 Apr 27 0:00
-8:00 - -08
# American Samoa
Zone Pacific/Pago_Pago 12:37:12 - LMT 1892 Jul 5
-11:22:48 - LMT 1911
-11:00 - SST # S=Samoa
Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
# Samoa (formerly and also known as Western Samoa)
# From Steffen Thorsen (2009-10-16):
# We have been in contact with the government of Samoa again, and received
# the following info:
#
# "Cabinet has now approved Daylight Saving to be effected next year
# commencing from the last Sunday of September 2010 and conclude first
# Sunday of April 2011."
#
# Background info:
# https://www.timeanddate.com/news/time/samoa-dst-plan-2009.html
#
# Samoa's Daylight Saving Time Act 2009 is available here, but does not
# contain any dates:
# http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%202009%20%28English%29%20-%20Final%207-7-091.pdf
# From Laupue Raymond Hughes (2010-10-07):
# Please see
# http://www.mcil.gov.ws
# the Ministry of Commerce, Industry and Labour (sideframe) "Last Sunday
# September 2010 (26/09/10) - adjust clocks forward from 12:00 midnight
# to 01:00am and First Sunday April 2011 (03/04/11) - adjust clocks
# backwards from 1:00am to 12:00am"
# From Laupue Raymond Hughes (2011-03-07):
# [http://www.mcil.gov.ws/ftcd/daylight_saving_2011.pdf]
#
# ... when the standard time strikes the hour of four o'clock (4.00am
# or 0400 Hours) on the 2nd April 2011, then all instruments used to
# measure standard time are to be adjusted/changed to three o'clock
# (3:00am or 0300Hrs).
# From David Zülke (2011-05-09):
# Subject: Samoa to move timezone from east to west of international date line
#
# http://www.morningstar.co.uk/uk/markets/newsfeeditem.aspx?id=138501958347963
# From Paul Eggert (2014-06-27):
# The International Date Line Act 2011
# http://www.parliament.gov.ws/images/ACTS/International_Date_Line_Act__2011_-_Eng.pdf
# changed Samoa from UT -11 to +13, effective "12 o'clock midnight, on
# Thursday 29th December 2011". The International Date Line was adjusted
# accordingly.
# From Laupue Raymond Hughes (2011-09-02):
# http://www.mcil.gov.ws/mcil_publications.html
#
# here is the official website publication for Samoa DST and dateline change
#
# DST
# Year End Time Start Time
# 2011 - - - - - - 24 September 3:00am to 4:00am
# 2012 01 April 4:00am to 3:00am - - - - - -
#
# Dateline Change skip Friday 30th Dec 2011
# Thursday 29th December 2011 23:59:59 Hours
# Saturday 31st December 2011 00:00:00 Hours
#
# From Nicholas Pereira (2012-09-10):
# Daylight Saving Time commences on Sunday 30th September 2012 and
# ends on Sunday 7th of April 2013....
# http://www.mcil.gov.ws/mcil_publications.html
#
# From Paul Eggert (2014-07-08):
# That web page currently lists transitions for 2012/3 and 2013/4.
# Assume the pattern instituted in 2012 will continue indefinitely.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule WS 2010 only - Sep lastSun 0:00 1 -
Rule WS 2011 only - Apr Sat>=1 4:00 0 -
Rule WS 2011 only - Sep lastSat 3:00 1 -
Rule WS 2012 max - Apr Sun>=1 4:00 0 -
Rule WS 2012 max - Sep lastSun 3:00 1 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Apia 12:33:04 - LMT 1892 Jul 5
-11:26:56 - LMT 1911
-11:30 - -1130 1950
-11:00 WS -11/-10 2011 Dec 29 24:00
13:00 WS +13/+14
# Solomon Is
# excludes Bougainville, for which see Papua New Guinea
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Guadalcanal 10:39:48 - LMT 1912 Oct # Honiara
11:00 - +11
# Tokelau
#
# From Gwillim Law (2011-12-29)
# A correspondent informed me that Tokelau, like Samoa, will be skipping
# December 31 this year ...
#
# From Steffen Thorsen (2012-07-25)
# ... we double checked by calling hotels and offices based in Tokelau asking
# about the time there, and they all told a time that agrees with UTC+13....
# Shanks says UT-10 from 1901 [but] ... there is a good chance the change
# actually was to UT-11 back then.
#
# From Paul Eggert (2012-07-25)
# A Google Books snippet of Appendix to the Journals of the House of
# Representatives of New Zealand, Session 1948,
# <https://books.google.com/books?id=ZaVCAQAAIAAJ>, page 65, says Tokelau
# was "11 hours slow on G.M.T." Go with Thorsen and assume Shanks & Pottenger
# are off by an hour starting in 1901.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Fakaofo -11:24:56 - LMT 1901
-11:00 - -11 2011 Dec 30
13:00 - +13
# Tonga
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Tonga 1999 only - Oct 7 2:00s 1:00 -
Rule Tonga 2000 only - Mar 19 2:00s 0 -
Rule Tonga 2000 2001 - Nov Sun>=1 2:00 1:00 -
Rule Tonga 2001 2002 - Jan lastSun 2:00 0 -
Rule Tonga 2016 only - Nov Sun>=1 2:00 1:00 -
Rule Tonga 2017 only - Jan Sun>=15 3:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tongatapu 12:19:20 - LMT 1901
12:20 - +1220 1941
13:00 - +13 1999
13:00 Tonga +13/+14
# Tuvalu
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Funafuti 11:56:52 - LMT 1901
12:00 - +12
# US minor outlying islands
# Howland, Baker
# Howland was mined for guano by American companies 1857-1878 and British
# 1886-1891; Baker was similar but exact dates are not known.
# Inhabited by civilians 1935-1942; U.S. military bases 1943-1944;
# uninhabited thereafter.
# Howland observed Hawaii Standard Time (UT -10:30) in 1937;
# see page 206 of Elgen M. Long and Marie K. Long,
# Amelia Earhart: the Mystery Solved, Simon & Schuster (2000).
# So most likely Howland and Baker observed Hawaii Time from 1935
# until they were abandoned after the war.
# Jarvis
# Mined for guano by American companies 1857-1879 and British 1883?-1891?.
# Inhabited by civilians 1935-1942; IGY scientific base 1957-1958;
# uninhabited thereafter.
# no information; was probably like Pacific/Kiritimati
# Johnston
#
# From Paul Eggert (2017-02-10):
# Sometimes Johnston kept Hawaii time, and sometimes it was an hour behind.
# Details are uncertain. We have no data for Johnston after 1970, so
# treat it like Hawaii for now. Since Johnston is now uninhabited,
# its link to Pacific/Honolulu is in the 'backward' file.
#
# In his memoirs of June 6th to October 4, 1945
# <http://www.315bw.org/Herb_Bach.htm> (2005), Herbert C. Bach writes,
# "We started our letdown to Kwajalein Atoll and landed there at 5:00 AM
# Johnston time, 1:30 AM Kwajalein time." This was in June 1945, and
# confirms that Johnston kept the same time as Honolulu in summer 1945.
#
# From Lyle McElhaney (2014-03-11):
# [W]hen JI was being used for that [atomic bomb] testing, the time being used
# was not Hawaiian time but rather the same time being used on the ships,
# which had a GMT offset of -11 hours. This apparently applied to at least the
# time from Operation Newsreel (Hardtack I/Teak shot, 1958-08-01) to the last
# Operation Fishbowl shot (Tightrope, 1962-11-04).... [See] Herman Hoerlin,
# "The United States High-Altitude Test Experience: A Review Emphasizing the
# Impact on the Environment", Los Alamos LA-6405, Oct 1976.
# https://www.fas.org/sgp/othergov/doe/lanl/docs1/00322994.pdf
# See the table on page 4 where he lists GMT and local times for the tests; a
# footnote for the JI tests reads that local time is "JI time = Hawaii Time
# Minus One Hour".
# Kingman
# uninhabited
# Midway
# See Pacific/Pago_Pago.
# Palmyra
# uninhabited since World War II; was probably like Pacific/Kiritimati
# Wake
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Wake 11:06:28 - LMT 1901
12:00 - +12
# Vanuatu
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Vanuatu 1983 only - Sep 25 0:00 1:00 -
Rule Vanuatu 1984 1991 - Mar Sun>=23 0:00 0 -
Rule Vanuatu 1984 only - Oct 23 0:00 1:00 -
Rule Vanuatu 1985 1991 - Sep Sun>=23 0:00 1:00 -
Rule Vanuatu 1992 1993 - Jan Sun>=23 0:00 0 -
Rule Vanuatu 1992 only - Oct Sun>=23 0:00 1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Efate 11:13:16 - LMT 1912 Jan 13 # Vila
11:00 Vanuatu +11/+12
# Wallis and Futuna
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Wallis 12:15:20 - LMT 1901
12:00 - +12
###############################################################################
# NOTES
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (2018-11-18):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# Another source occasionally used is Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
# I found in the UCLA library.
#
# For data circa 1899, a common source is:
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
# https://www.jstor.org/stable/1774359
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# I invented the abbreviation marked "*".
# The following abbreviations are from other sources.
# Corrections are welcome!
# std dst
# LMT Local Mean Time
# 8:00 AWST AWDT Western Australia
# 9:30 ACST ACDT Central Australia
# 10:00 AEST AEDT Eastern Australia
# 10:00 GST GDT* Guam through 2000
# 10:00 ChST Chamorro
# 11:30 NZMT NZST New Zealand through 1945
# 12:00 NZST NZDT New Zealand 1946-present
# -11:00 SST Samoa
# -10:00 HST Hawaii
#
# See the 'northamerica' file for Hawaii.
# See the 'southamerica' file for Easter I and the Galápagos Is.
###############################################################################
# Australia
# From Paul Eggert (2014-06-30):
# Daylight saving time has long been controversial in Australia, pitting
# region against region, rural against urban, and local against global.
# For example, in her review of Graeme Davison's _The Unforgiving
# Minute: how Australians learned to tell the time_ (1993), Perth native
# Phillipa J Martyr wrote, "The section entitled 'Saving Daylight' was
# very informative, but was (as can, sadly, only be expected from a
# Melbourne-based study) replete with the usual chuckleheaded
# Queenslanders and straw-chewing yokels from the West prattling fables
# about fading curtains and crazed farm animals."
# Electronic Journal of Australian and New Zealand History (1997-03-03)
# http://www.jcu.edu.au/aff/history/reviews/davison.htm
# From Paul Eggert (2005-12-08):
# Implementation Dates of Daylight Saving Time within Australia
# http://www.bom.gov.au/climate/averages/tables/dst_times.shtml
# summarizes daylight saving issues in Australia.
# From Arthur David Olson (2005-12-12):
# Lawlink NSW:Daylight Saving in New South Wales
# http://www.lawlink.nsw.gov.au/lawlink/Corporate/ll_agdinfo.nsf/pages/community_relations_daylight_saving
# covers New South Wales in particular.
# From John Mackin (1991-03-06):
# We in Australia have _never_ referred to DST as 'daylight' time.
# It is called 'summer' time. Now by a happy coincidence, 'summer'
# and 'standard' happen to start with the same letter; hence, the
# abbreviation does _not_ change...
# The legislation does not actually define abbreviations, at least
# in this State, but the abbreviation is just commonly taken to be the
# initials of the phrase, and the legislation here uniformly uses
# the phrase 'summer time' and does not use the phrase 'daylight
# time'.
# Announcers on the Commonwealth radio network, the ABC (for Australian
# Broadcasting Commission), use the phrases 'Eastern Standard Time'
# or 'Eastern Summer Time'. (Note, though, that as I say in the
# current australasia file, there is really no such thing.) Announcers
# on its overseas service, Radio Australia, use the same phrases
# prefixed by the word 'Australian' when referring to local times;
# time announcements on that service, naturally enough, are made in UTC.
# From Paul Eggert (2014-06-30):
#
# Inspired by Mackin's remarks quoted above, earlier versions of this
# file used "EST" for both Eastern Standard Time and Eastern Summer
# Time in Australia, and similarly for "CST", "CWST", and "WST".
# However, these abbreviations were confusing and were not common
# practice among Australians, and there were justifiable complaints
# about them, so I attempted to survey current Australian usage.
# For the tz database, the full English phrase is not that important;
# what matters is the abbreviation. It's difficult to survey the web
# directly for abbreviation usage, as there are so many false hits for
# strings like "EST" and "EDT", so I looked for pages that defined an
# abbreviation for eastern or central DST in Australia, and got the
# following numbers of unique hits for the listed Google queries:
#
# 10 "Eastern Daylight Time AEST" site:au [some are false hits]
# 10 "Eastern Summer Time AEST" site:au
# 10 "Summer Time AEDT" site:au
# 13 "EDST Eastern Daylight Saving Time" site:au
# 18 "Summer Time ESST" site:au
# 28 "Eastern Daylight Saving Time EDST" site:au
# 39 "EDT Eastern Daylight Time" site:au [some are false hits]
# 53 "Eastern Daylight Time EDT" site:au [some are false hits]
# 54 "AEDT Australian Eastern Daylight Time" site:au
# 182 "Eastern Daylight Time AEDT" site:au
#
# 17 "Central Daylight Time CDT" site:au [some are false hits]
# 46 "Central Daylight Time ACDT" site:au
#
# I tried several other variants (e.g., "Eastern Summer Time EST") but
# they all returned fewer than 10 unique hits. I also looked for pages
# mentioning both "western standard time" and an abbreviation, since
# there is no WST in the US to generate false hits, and found:
#
# 156 "western standard time" AWST site:au
# 226 "western standard time" WST site:au
#
# I then surveyed the top ten newspapers in Australia by circulation as
# listed in Wikipedia, using Google queries like "AEDT site:heraldsun.com.au"
# and obtaining estimated counts from the initial page of search results.
# All ten papers greatly preferred "AEDT" to "EDT". The papers
# surveyed were the Herald Sun, The Daily Telegraph, The Courier-Mail,
# The Sydney Morning Herald, The West Australian, The Age, The Advertiser,
# The Australian, The Financial Review, and The Herald (Newcastle).
#
# I also searched for historical usage, to see whether abbreviations
# like "AEDT" are new. A Trove search <http://trove.nla.gov.au/>
# found only one newspaper (The Canberra Times) with a house style
# dating back to the 1970s, I expect because other newspapers weren't
# fully indexed. The Canberra Times strongly preferred abbreviations
# like "AEDT". The first occurrence of "AEDT" was a World Weather
# column (1971-11-17, page 24), and of "ACDT" was a Scoreboard column
# (1993-01-24, p 16). The style was the typical usage but was not
# strictly enforced; for example, "Welcome to the twilight zones ..."
# (1994-10-29, p 1) uses the abbreviations AEST/AEDT, CST/CDT, and
# WST, and goes on to say, "The confusion and frustration some feel
# about the lack of uniformity among Australia's six states and two
# territories has prompted one group to form its very own political
# party -- the Sydney-based Daylight Saving Extension Party."
#
# I also surveyed federal government sources. They did not agree:
#
# The Australian Government (2014-03-26)
# http://australia.gov.au/about-australia/our-country/time
# (This document was produced by the Department of Finance.)
# AEST ACST AWST AEDT ACDT
#
# Bureau of Meteorology (2012-11-08)
# http://www.bom.gov.au/climate/averages/tables/daysavtm.shtml
# EST CST WST EDT CDT
#
# Civil Aviation Safety Authority (undated)
# http://services.casa.gov.au/outnback/inc/pages/episode3/episode-3_time_zones.shtml
# EST CST WST (no abbreviations given for DST)
#
# Geoscience Australia (2011-11-24)
# http://www.ga.gov.au/geodesy/astro/sunrise.jsp
# AEST ACST AWST AEDT ACDT
#
# Parliamentary Library (2008-11-10)
# https://www.aph.gov.au/binaries/library/pubs/rp/2008-09/09rp14.pdf
# EST CST WST preferred for standard time; AEST AEDT ACST ACDT also used
#
# The Transport Safety Bureau has an extensive series of accident reports,
# and investigators seem to use whatever abbreviation they like.
# Googling site:atsb.gov.au found the following number of unique hits:
# 311 "ESuT", 195 "EDT", 26 "AEDT", 83 "CSuT", 46 "CDT".
# "_SuT" tended to appear in older reports, and "A_DT" tended to
# appear in reports of events with international implications.
#
# From the above it appears that there is a working consensus in
# Australia to use trailing "DT" for daylight saving time; although
# some sources use trailing "SST" or "ST" or "SuT" they are by far in
# the minority. The case for leading "A" is weaker, but since it
# seems to be preferred in the overall web and is preferred in all
# the leading newspaper websites and in many government departments,
# it has a stronger case than omitting the leading "A". The current
# version of the database therefore uses abbreviations like "AEST" and
# "AEDT" for Australian time zones.
# From Paul Eggert (1995-12-19):
# Shanks & Pottenger report 2:00 for all autumn changes in Australia and NZ.
# Mark Prior writes that his newspaper
# reports that NSW's fall 1995 change will occur at 2:00,
# but Robert Elz says it's been 3:00 in Victoria since 1970
# and perhaps the newspaper's '2:00' is referring to standard time.
# For now we'll continue to assume 2:00s for changes since 1960.
# From Eric Ulevik (1998-01-05):
#
# Here are some URLs to Australian time legislation. These URLs are stable,
# and should probably be included in the data file. There are probably more
# relevant entries in this database.
#
# NSW (including LHI and Broken Hill):
# Standard Time Act 1987 (updated 1995-04-04)
# https://www.austlii.edu.au/au/legis/nsw/consol_act/sta1987137/index.html
# ACT
# Standard Time and Summer Time Act 1972
# https://www.austlii.edu.au/au/legis/act/consol_act/stasta1972279/index.html
# SA
# Standard Time Act, 1898
# https://www.austlii.edu.au/au/legis/sa/consol_act/sta1898137/index.html
# From David Grosz (2005-06-13):
# It was announced last week that Daylight Saving would be extended by
# one week next year to allow for the 2006 Commonwealth Games.
# Daylight Saving is now to end for next year only on the first Sunday
# in April instead of the last Sunday in March.
#
# From Gwillim Law (2005-06-14):
# I did some Googling and found that all of those states (and territory) plan
# to extend DST together in 2006.
# ACT: http://www.cmd.act.gov.au/mediareleases/fileread.cfm?file=86.txt
# New South Wales: http://www.thecouriermail.news.com.au/common/story_page/0,5936,15538869%255E1702,00.html
# South Australia: http://www.news.com.au/story/0,10117,15555031-1246,00.html
# Tasmania: http://www.media.tas.gov.au/release.php?id=14772
# Victoria: I wasn't able to find anything separate, but the other articles
# allude to it.
# But not Queensland
# http://www.news.com.au/story/0,10117,15564030-1248,00.html
# Northern Territory
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The NORTHERN TERRITORY.. [ Courtesy N.T. Dept of the Chief Minister ]
# # [ Nov 1990 ]
# # N.T. have never utilised any DST due to sub-tropical/tropical location.
# ...
# Zone Australia/North 9:30 - CST
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# the Northern Territory do[es] not have daylight saving.
# Western Australia
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of WESTERN AUSTRALIA.. [ Courtesy W.A. dept Premier+Cabinet ]
# # [ Nov 1990 ]
# # W.A. suffers from a great deal of public and political opposition to
# # DST in principle. A bill is brought before parliament in most years, but
# # usually defeated either in the upper house, or in party caucus
# # before reaching parliament.
# ...
# Zone Australia/West 8:00 AW %sST
# ...
# Rule AW 1974 only - Oct lastSun 2:00 1:00 D
# Rule AW 1975 only - Mar Sun>=1 3:00 0 W
# Rule AW 1983 only - Oct lastSun 2:00 1:00 D
# Rule AW 1984 only - Mar Sun>=1 3:00 0 W
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# Western Australia...do[es] not have daylight saving.
# From John D. Newman via Bradley White (1991-11-02):
# Western Australia is still on "winter time". Some DH in Sydney
# rang me at home a few days ago at 6.00am. (He had just arrived at
# work at 9.00am.)
# W.A. is switching to Summer Time on Nov 17th just to confuse
# everybody again.
# From Arthur David Olson (1992-03-08):
# The 1992 ending date used in the rules is a best guess;
# it matches what was used in the past.
# The Australian Bureau of Meteorology FAQ
# http://www.bom.gov.au/faq/faqgen.htm
# (1999-09-27) writes that Giles Meteorological Station uses
# South Australian time even though it's located in Western Australia.
# From Paul Eggert (2018-04-01):
# The Guardian Express of Perth, Australia reported today that the
# government decided to advance the clocks permanently on January 1,
# 2019, from UT +08 to UT +09. The article noted that an exemption
# would be made for people aged 61 and over, who "can apply in writing
# to have the extra hour of sunshine removed from their area." See:
# Daylight saving coming to WA in 2019. Guardian Express. 2018-04-01.
# https://www.communitynews.com.au/guardian-express/news/exclusive-daylight-savings-coming-wa-summer-2018/
# Queensland
# From Paul Eggert (2018-02-26):
# I lack access to the following source for Queensland DST:
# Pearce C. History of daylight saving time in Queensland.
# Queensland Hist J. 2017 Aug;23(6):389-403
# https://search.informit.com.au/documentSummary;dn=994682348436426;res=IELHSS
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of QUEENSLAND.. [ Courtesy Qld. Dept Premier Econ&Trade Devel ]
# # [ Dec 1990 ]
# ...
# Zone Australia/Queensland 10:00 AQ %sST
# ...
# Rule AQ 1971 only - Oct lastSun 2:00 1:00 D
# Rule AQ 1972 only - Feb lastSun 3:00 0 E
# Rule AQ 1989 max - Oct lastSun 2:00 1:00 D
# Rule AQ 1990 max - Mar Sun>=1 3:00 0 E
# From Bradley White (1989-12-24):
# "Australia/Queensland" now observes daylight time (i.e. from
# October 1989).
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# ...Queensland...[has] agreed to end daylight saving
# at 3am tomorrow (March 3)...
# From John Mackin (1991-03-06):
# I can certainly confirm for my part that Daylight Saving in NSW did in fact
# end on Sunday, 3 March. I don't know at what hour, though. (It surprised
# me.)
# From Bradley White (1992-03-08):
# ...there was recently a referendum in Queensland which resulted
# in the experimental daylight saving system being abandoned. So, ...
# ...
# Rule QLD 1989 1991 - Oct lastSun 2:00 1:00 D
# Rule QLD 1990 1992 - Mar Sun>=1 3:00 0 S
# ...
# From Arthur David Olson (1992-03-08):
# The chosen rules the union of the 1971/1972 change and the 1989-1992 changes.
# From Christopher Hunt (2006-11-21), after an advance warning
# from Jesper Nørgaard Welen (2006-11-01):
# WA are trialing DST for three years.
# http://www.parliament.wa.gov.au/parliament/bills.nsf/9A1B183144403DA54825721200088DF1/$File/Bill175-1B.pdf
# From Rives McDow (2002-04-09):
# The most interesting region I have found consists of three towns on the
# southern coast.... South Australia observes daylight saving time; Western
# Australia does not. The two states are one and a half hours apart. The
# residents decided to forget about this nonsense of changing the clock so
# much and set the local time 20 hours and 45 minutes from the
# international date line, or right in the middle of the time of South
# Australia and Western Australia....
#
# From Paul Eggert (2002-04-09):
# This is confirmed by the section entitled
# "What's the deal with time zones???" in
# http://www.earthsci.unimelb.edu.au/~awatkins/null.html
#
# From Alex Livingston (2006-12-07):
# ... it was just on four years ago that I drove along the Eyre Highway,
# which passes through eastern Western Australia close to the southern
# coast of the continent.
#
# I paid particular attention to the time kept there. There can be no
# dispute that UTC+08:45 was considered "the time" from the border
# village just inside the border with South Australia to as far west
# as just east of Caiguna. There can also be no dispute that Eucla is
# the largest population centre in this zone....
#
# Now that Western Australia is observing daylight saving, the
# question arose whether this part of the state would follow suit. I
# just called the border village and confirmed that indeed they have,
# meaning that they are now observing UTC+09:45.
#
# (2006-12-09):
# I personally doubt that either experimentation with daylight saving
# in WA or its introduction in SA had anything to do with the genesis
# of this time zone. My hunch is that it's been around since well
# before 1975. I remember seeing it noted on road maps decades ago.
#
# From Gilmore Davidson (2019-04-08):
# https://www.abc.net.au/news/2019-04-08/this-remote-stretch-of-desert-has-its-own-custom-time-zone/10981000
# ... include[s] a rough description of the geographical boundaries...
# "The time zone exists for about 340 kilometres and takes in the tiny
# roadhouse communities of Cocklebiddy, Madura, Eucla and Border Village."
# ... and an indication that the zone has definitely been in existence
# since before the 1970 cut-off of the database ...
# From Paul Eggert (2019-05-17):
# That ABC Esperance story by Christien de Garis also says:
# Although the Central Western Time Zone is not officially recognised (your
# phones won't automatically change), there is a sign instructing you which
# way to wind your clocks 45 minutes and scrawled underneath one of them in
# Texta is the word: 'Why'?
# "Good question," Mr Pike said.
# "I don't even know that, and it's been going for over 50 years."
# From Paul Eggert (2006-12-15):
# For lack of better info, assume the tradition dates back to the
# introduction of standard time in 1895.
# southeast Australia
#
# From Paul Eggert (2007-07-23):
# Starting autumn 2008 Victoria, NSW, South Australia, Tasmania and the ACT
# end DST the first Sunday in April and start DST the first Sunday in October.
# http://www.theage.com.au/news/national/daylight-savings-to-span-six-months/2007/06/27/1182623966703.html
# South Australia
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# ...South Australia...[has] agreed to end daylight saving
# at 3am tomorrow (March 3)...
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of SOUTH AUSTRALIA....[ Courtesy of S.A. Dept of Labour ]
# # [ Nov 1990 ]
# ...
# Zone Australia/South 9:30 AS %sST
# ...
# Rule AS 1971 max - Oct lastSun 2:00 1:00 D
# Rule AS 1972 1985 - Mar Sun>=1 3:00 0 C
# Rule AS 1986 1990 - Mar Sun>=15 3:00 0 C
# Rule AS 1991 max - Mar Sun>=1 3:00 0 C
# From Bradley White (1992-03-11):
# Recent correspondence with a friend in Adelaide
# contained the following exchange: "Due to the Adelaide Festival,
# South Australia delays setting back our clocks for a few weeks."
# From Robert Elz (1992-03-13):
# I heard that apparently (or at least, it appears that)
# South Aus will have an extra 3 weeks daylight saving every even
# numbered year (from 1990). That's when the Adelaide Festival
# is on...
# From Robert Elz (1992-03-16, 00:57:07 +1000):
# DST didn't end in Adelaide today (yesterday)....
# But whether it's "4th Sunday" or "2nd last Sunday" I have no idea whatever...
# (it's just as likely to be "the Sunday we pick for this year"...).
# From Bradley White (1994-04-11):
# If Sun, 15 March, 1992 was at +1030 as kre asserts, but yet Sun, 20 March,
# 1994 was at +0930 as John Connolly's customer seems to assert, then I can
# only conclude that the actual rule is more complicated....
# From John Warburton (1994-10-07):
# The new Daylight Savings dates for South Australia ...
# was gazetted in the Government Hansard on Sep 26 1994....
# start on last Sunday in October and end in last sunday in March.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Tasmania
# The rules for 1967 through 1991 were reported by George Shepherd
# via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of TASMANIA.. [Courtesy Tasmanian Dept of Premier + Cabinet ]
# # [ Nov 1990 ]
# From Bill Hart via Guy Harris (1991-10-10):
# Oh yes, the new daylight savings rules are uniquely tasmanian, we have
# 6 weeks a year now when we are out of sync with the rest of Australia
# (but nothing new about that).
# From Alex Livingston (1999-10-04):
# I heard on the ABC (Australian Broadcasting Corporation) radio news on the
# (long) weekend that Tasmania, which usually goes its own way in this regard,
# has decided to join with most of NSW, the ACT, and most of Victoria
# (Australia) and start daylight saving on the last Sunday in August in 2000
# instead of the first Sunday in October.
# Sim Alam (2000-07-03) reported a legal citation for the 2000/2001 rules:
# http://www.thelaw.tas.gov.au/fragview/42++1968+GS3A@EN+2000070300
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Victoria
# The rules for 1971 through 1991 were reported by George Shepherd
# via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of VICTORIA.. [ Courtesy of Vic. Dept of Premier + Cabinet ]
# # [ Nov 1990 ]
# From Scott Harrington (2001-08-29):
# On KQED's "City Arts and Lectures" program last night I heard an
# interesting story about daylight savings time. Dr. John Heilbron was
# discussing his book "The Sun in the Church: Cathedrals as Solar
# Observatories"[1], and in particular the Shrine of Remembrance[2] located
# in Melbourne, Australia.
#
# Apparently the shrine's main purpose is a beam of sunlight which
# illuminates a special spot on the floor at the 11th hour of the 11th day
# of the 11th month (Remembrance Day) every year in memory of Australia's
# fallen WWI soldiers. And if you go there on Nov. 11, at 11am local time,
# you will indeed see the sunbeam illuminate the special spot at the
# expected time.
#
# However, that is only because of some special mirror contraption that had
# to be employed, since due to daylight savings time, the true solar time of
# the remembrance moment occurs one hour later (or earlier?). Perhaps
# someone with more information on this jury-rig can tell us more.
#
# [1] http://www.hup.harvard.edu/catalog/HEISUN.html
# [2] http://www.shrine.org.au
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# New South Wales
# From Arthur David Olson:
# New South Wales and subjurisdictions have their own ideas of a fun time.
# Based on law library research by John Mackin,
# who notes:
# In Australia, time is not legislated federally, but rather by the
# individual states. Thus, while such terms as "Eastern Standard Time"
# [I mean, of course, Australian EST, not any other kind] are in common
# use, _they have NO REAL MEANING_, as they are not defined in the
# legislation. This is very important to understand.
# I have researched New South Wales time only...
# From Eric Ulevik (1999-05-26):
# DST will start in NSW on the last Sunday of August, rather than the usual
# October in 2000. See: Matthew Moore,
# Two months more daylight saving, Sydney Morning Herald (1999-05-26).
# http://www.smh.com.au/news/9905/26/pageone/pageone4.html
# From Paul Eggert (1999-09-27):
# See the following official NSW source:
# Daylight Saving in New South Wales.
# http://dir.gis.nsw.gov.au/cgi-bin/genobject/document/other/daylightsaving/tigGmZ
#
# Narrabri Shire (NSW) council has announced it will ignore the extension of
# daylight saving next year. See:
# Narrabri Council to ignore daylight saving
# http://abc.net.au/news/regionals/neweng/monthly/regeng-22jul1999-1.htm
# (1999-07-22). For now, we'll wait to see if this really happens.
#
# Victoria will follow NSW. See:
# Vic to extend daylight saving (1999-07-28)
# http://abc.net.au/local/news/olympics/1999/07/item19990728112314_1.htm
#
# However, South Australia rejected the DST request. See:
# South Australia rejects Olympics daylight savings request (1999-07-19)
# http://abc.net.au/news/olympics/1999/07/item19990719151754_1.htm
#
# Queensland also will not observe DST for the Olympics. See:
# Qld says no to daylight savings for Olympics
# http://abc.net.au/news/olympics/1999/06/item19990601114608_1.htm
# (1999-06-01), which quotes Queensland Premier Peter Beattie as saying
# "Look you've got to remember in my family when this came up last time
# I voted for it, my wife voted against it and she said to me it's all very
# well for you, you don't have to worry about getting the children out of
# bed, getting them to school, getting them to sleep at night.
# I've been through all this argument domestically...my wife rules."
#
# Broken Hill will stick with South Australian time in 2000. See:
# Broken Hill to be behind the times (1999-07-21)
# http://abc.net.au/news/regionals/brokenh/monthly/regbrok-21jul1999-6.htm
# IATA SSIM (1998-09) says that the spring 2000 change for Australian
# Capital Territory, New South Wales except Lord Howe Island and Broken
# Hill, and Victoria will be August 27, presumably due to the Sydney Olympics.
# From Eric Ulevik, referring to Sydney's Sun Herald (2000-08-13), page 29:
# The Queensland Premier Peter Beattie is encouraging northern NSW
# towns to use Queensland time.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Yancowinna
# From John Mackin (1989-01-04):
# 'Broken Hill' means the County of Yancowinna.
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # YANCOWINNA.. [ Confirmation courtesy of Broken Hill Postmaster ]
# # [ Dec 1990 ]
# ...
# # Yancowinna uses Central Standard Time, despite [its] location on the
# # New South Wales side of the S.A. border. Most business and social dealings
# # are with CST zones, therefore CST is legislated by local government
# # although the switch to Summer Time occurs in line with N.S.W. There have
# # been years when this did not apply, but the historical data is not
# # presently available.
# Zone Australia/Yancowinna 9:30 AY %sST
# ...
# Rule AY 1971 1985 - Oct lastSun 2:00 1:00 D
# Rule AY 1972 only - Feb lastSun 3:00 0 C
# [followed by other Rules]
# Lord Howe Island
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# LHI... [ Courtesy of Pauline Van Winsen ]
# [ Dec 1990 ]
# Lord Howe Island is located off the New South Wales coast, and is half an
# hour ahead of NSW time.
# From James Lonergan, Secretary, Lord Howe Island Board (2000-01-27):
# Lord Howe Island summer time in 2000/2001 will commence on the same
# date as the rest of NSW (i.e. 2000-08-27). For your information the
# Lord Howe Island Board (controlling authority for the Island) is
# seeking the community's views on various options for summer time
# arrangements on the Island, e.g. advance clocks by 1 full hour
# instead of only 30 minutes. [Dependent] on the wishes of residents
# the Board may approach the NSW government to change the existing
# arrangements. The starting date for summer time on the Island will
# however always coincide with the rest of NSW.
# From James Lonergan, Secretary, Lord Howe Island Board (2000-10-25):
# Lord Howe Island advances clocks by 30 minutes during DST in NSW and retards
# clocks by 30 minutes when DST finishes. Since DST was most recently
# introduced in NSW, the "changeover" time on the Island has been 02:00 as
# shown on clocks on LHI. I guess this means that for 30 minutes at the start
# of DST, LHI is actually 1 hour ahead of the rest of NSW.
# From Paul Eggert (2006-03-22):
# For Lord Howe dates we use Shanks & Pottenger through 1989, and
# Lonergan thereafter. For times we use Lonergan.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# From Steffen Thorsen (2009-04-28):
# According to the official press release, South Australia's extended daylight
# saving period will continue with the same rules as used during the 2008-2009
# summer (southern hemisphere).
#
# From
# http://www.safework.sa.gov.au/uploaded_files/DaylightDatesSet.pdf
# The extended daylight saving period that South Australia has been trialling
# for over the last year is now set to be ongoing.
# Daylight saving will continue to start on the first Sunday in October each
# year and finish on the first Sunday in April the following year.
# Industrial Relations Minister, Paul Caica, says this provides South Australia
# with a consistent half hour time difference with NSW, Victoria, Tasmania and
# the ACT for all 52 weeks of the year...
#
# We have a wrap-up here:
# https://www.timeanddate.com/news/time/south-australia-extends-dst.html
###############################################################################
# New Zealand
# From Mark Davies (1990-10-03):
# the 1989/90 year was a trial of an extended "daylight saving" period.
# This trial was deemed successful and the extended period adopted for
# subsequent years (with the addition of a further week at the start).
# source - phone call to Ministry of Internal Affairs Head Office.
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The Country of New Zealand (Australia's east island -) Gee they hate that!
# # or is Australia the west island of N.Z.
# # [ courtesy of Geoff Tribble.. Auckland N.Z. ]
# # [ Nov 1990 ]
# ...
# Rule NZ 1974 1988 - Oct lastSun 2:00 1:00 D
# Rule NZ 1989 max - Oct Sun>=1 2:00 1:00 D
# Rule NZ 1975 1989 - Mar Sun>=1 3:00 0 S
# Rule NZ 1990 max - Mar lastSun 3:00 0 S
# ...
# Zone NZ 12:00 NZ NZ%sT # New Zealand
# Zone NZ-CHAT 12:45 - NZ-CHAT # Chatham Island
# From Arthur David Olson (1992-03-08):
# The chosen rules use the Davies October 8 values for the start of DST in 1989
# rather than the October 1 value.
# From Paul Eggert (1995-12-19);
# Shank & Pottenger report 2:00 for all autumn changes in Australia and NZ.
# Robert Uzgalis writes that the New Zealand Daylight
# Savings Time Order in Council dated 1990-06-18 specifies 2:00 standard
# time on both the first Sunday in October and the third Sunday in March.
# As with Australia, we'll assume the tradition is 2:00s, not 2:00.
#
# From Paul Eggert (2006-03-22):
# The Department of Internal Affairs (DIA) maintains a brief history,
# as does Carol Squires; see tz-link.html for the full references.
# Use these sources in preference to Shanks & Pottenger.
#
# For Chatham, IATA SSIM (1991/1999) gives the NZ rules but with
# transitions at 2:45 local standard time; this confirms that Chatham
# is always exactly 45 minutes ahead of Auckland.
# From Colin Sharples (2007-04-30):
# DST will now start on the last Sunday in September, and end on the
# first Sunday in April. The changes take effect this year, meaning
# that DST will begin on 2007-09-30 2008-04-06.
# http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Services-Daylight-Saving-Daylight-saving-to-be-extended
# From Paul Eggert (2014-07-14):
# Chatham Island time was formally standardized on 1957-01-01 by
# New Zealand's Standard Time Amendment Act 1956 (1956-10-26).
# https://www.austlii.edu.au/nz/legis/hist_act/staa19561956n100244.pdf
# According to Google Books snippet view, a speaker in the New Zealand
# parliamentary debates in 1956 said "Clause 78 makes provision for standard
# time in the Chatham Islands. The time there is 45 minutes in advance of New
# Zealand time. I understand that is the time they keep locally, anyhow."
# For now, assume this practice goes back to the introduction of standard time
# in New Zealand, as this would make Chatham Islands time almost exactly match
# LMT back when New Zealand was at UT +11:30; also, assume Chatham Islands did
# not observe New Zealand's prewar DST.
###############################################################################
# Bonin (Ogasawara) Islands and Marcus Island (Minami-Tori-shima)
# From Wakaba (2019-01-28) via Phake Nick:
# National Diet Library of Japan has several reports by Japanese Government
# officers that describe the time used in islands when they visited there.
# According to them (and other sources such as newspapers), standard time UTC
# + 10 (JST + 1) and DST UTC + 11 (JST + 2) was used until its return to Japan
# at 1968-06-26 00:00 JST. The exact periods of DST are still unknown.
# I guessed Guam, Mariana, and Bonin and Marcus districts might have
# synchronized their DST periods, but reports imply they had their own
# decisions, i.e. there were three or more different time zones....
#
# https://wiki.suikawiki.org/n/小笠原諸島の標準時
# From Phake Nick (2019-02-12):
# Because their last time change to return to Japanese time when they returned
# to Japanese rule was right before 1970, ... per the current tz database
# rule, the information doesn't warrant creation of a new timezone for Bonin
# Islands itself and is thus as an anecdotal note for interest purpose only.
# ... [The abovementioned link] described some special timekeeping phenomenon
# regarding Marcus island, another remote island currently owned by Japanese
# in the same administrative unit as Bonin Islands. Many reports claim that
# the American coastal guard on the American quarter of the island use its own
# coastal guard time, and most sources describe the time as UTC+11, being two
# hours faster than JST used by some Japanese personnel on the island. Some
# sites describe it as same as Wake Island/Guam time although it would be
# incorrect to be same as Guam. And then in a few Japanese governmental
# report from 1980s (from National Institute of Information and Communications
# Technology) regarding the construction of VLBI facility on the Marcus
# Island, it claimed that there are three time standards being used on the
# island at the time which include not just JST (UTC+9) or [US]CG time
# (UTC+11) but also a JMSDF time (UTC+10) (Japan Maritime Self-Defense
# Force). Unfortunately there are no other sources that mentioned such time
# and there are also no information on things like how the time was used.
# Fiji
# Howse writes (p 153) that in 1879 the British governor of Fiji
# enacted an ordinance standardizing the islands on Antipodean Time
# instead of the American system (which was one day behind).
# From Rives McDow (1998-10-08):
# Fiji will introduce DST effective 0200 local time, 1998-11-01
# until 0300 local time 1999-02-28. Each year the DST period will
# be from the first Sunday in November until the last Sunday in February.
# From Paul Eggert (2000-01-08):
# IATA SSIM (1999-09) says DST ends 0100 local time. Go with McDow.
# From the BBC World Service in
# http://news.bbc.co.uk/2/hi/asia-pacific/205226.stm (1998-10-31 16:03 UTC):
# The Fijian government says the main reasons for the time change is to
# improve productivity and reduce road accidents.... [T]he move is also
# intended to boost Fiji's ability to attract tourists to witness the dawning
# of the new millennium.
# http://www.fiji.gov.fj/press/2000_09/2000_09_13-05.shtml (2000-09-13)
# reports that Fiji has discontinued DST.
# Kiribati
# From Paul Eggert (1996-01-22):
# Today's _Wall Street Journal_ (page 1) reports that Kiribati
# "declared it the same day [throughout] the country as of Jan. 1, 1995"
# as part of the competition to be first into the 21st century.
# From Kerry Shetline (2018-02-03):
# December 31 was the day that was skipped, so that the transition
# would be from Friday December 30, 1994 to Sunday January 1, 1995.
# From Paul Eggert (2018-02-04):
# One source for this is page 202 of: Bartky IR. One Time Fits All:
# The Campaigns for Global Uniformity (2007).
# Kwajalein
# From an AP article (1993-08-22):
# "The nearly 3,000 Americans living on this remote Pacific atoll have a good
# excuse for not remembering Saturday night: there wasn't one. Residents were
# going to bed Friday night and waking up Sunday morning because at midnight
# -- 8 A.M. Eastern daylight time on Saturday -- Kwajalein was jumping from
# one side of the international date line to the other."
# "In Marshall Islands, Friday is followed by Sunday", NY Times. 1993-08-22.
# https://www.nytimes.com/1993/08/22/world/in-marshall-islands-friday-is-followed-by-sunday.html
# From Phake Nick (2018-10-27):
# <https://wiki.suikawiki.org/n/南洋群島の標準時> ... pointed out that
# currently tzdata say Pacific/Kwajalein switched from GMT+11 to GMT-12 in
# 1969 October without explanation, however an 1993 article from NYT say it
# synchorized its day with US mainland about 40 years ago and thus the switch
# should occur at around 1950s instead.
#
# From Paul Eggert (2018-11-18):
# The NYT (actually, AP) article is vague and possibly wrong about this.
# The article says the earlier switch was "40 years ago when the United States
# Army established a missile test range here". However, the Kwajalein Test
# Center was established on 1960-10-01 and was run by the US Navy. It was
# transferred to the US Army on 1964-07-01. See "Seize the High Ground"
# <https://history.army.mil/html/books/070/70-88-1/cmhPub_70-88-1.pdf>.
# Given that Shanks was right on the money about the 1993 change, I'm inclined
# to take Shanks's word for the 1969 change unless we find better evidence.
# N Mariana Is, Guam
# From Phake Nick (2018-10-27):
# Guam Island was briefly annexed by Japan during ... year 1941-1944 ...
# however there are no detailed information about what time it use during that
# period. It would probably be reasonable to assume Guam use GMT+9 during
# that period of time like the surrounding area.
# From Paul Eggert (2018-11-18):
# Howse writes (p 153) "The Spaniards, on the other hand, reached the
# Philippines and the Ladrones from America," and implies that the Ladrones
# (now called the Marianas) kept American date for quite some time.
# For now, we assume the Ladrones switched at the same time as the Philippines;
# see Asia/Manila.
#
# Use 1941-12-10 and 1944-07-31 for Guam WWII transitions, as the rough start
# and end of Japanese control of Agana. We don't know whether the Northern
# Marianas followed Guam's DST rules from 1959 through 1977; for now, assume
# they did as that avoids the need for a separate zone due to our 1970 cutoff.
#
# US Public Law 106-564 (2000-12-23) made UT +10 the official standard time,
# under the name "Chamorro Standard Time". There is no official abbreviation,
# but Congressman Robert A. Underwood, author of the bill that became law,
# wrote in a press release (2000-12-27) that he will seek the use of "ChST".
# See also the commentary for Micronesia.
# Marshall Is
# See the commentary for Micronesia.
# Micronesia (and nearby)
# From Paul Eggert (2018-11-18):
# Like the Ladrones (see Guam commentary), assume the Spanish East Indies
# kept American time until the Philippines switched at the end of 1844.
# Alan Eugene Davis writes (1996-03-16),
# "I am certain, having lived there for the past decade, that 'Truk'
# (now properly known as Chuuk) ... is in the time zone GMT+10."
#
# Shanks & Pottenger write that Truk switched from UT +10 to +11
# on 1978-10-01; ignore this for now.
# From Paul Eggert (1999-10-29):
# The Federated States of Micronesia Visitors Board writes in
# The Federated States of Micronesia - Visitor Information (1999-01-26)
# http://www.fsmgov.org/info/clocks.html
# that Truk and Yap are UT +10, and Ponape and Kosrae are +11.
# We don't know when Kosrae switched from +12; assume January 1 for now.
# From Phake Nick (2018-10-27):
#
# From a Japanese wiki site https://wiki.suikawiki.org/n/南洋群島の標準時
# ...
# For "Southern Islands" (modern region of Mariana + Palau + Federation of
# Micronesia + Marshall Islands):
#
# A 1906 Japanese magazine shown the Caroline Islands and Mariana Islands
# who was occupied by Germany at the time as GMT+10, together with the like
# of German New Guinea. However there is a marking saying it have not been
# implemented (yet). No further information after that were found.
#
# Japan invaded those islands in 1914, and records shows that they were
# instructed to use JST at the time.
#
# 1915 January telecommunication record on the Jaluit Atoll shows they use
# the meridian of 170E as standard time (GMT+11:20), which is similar to the
# longitude of the atoll.
# 1915 February record say the 170E standard time is to be used until
# February 9 noon, and after February 9 noon they are to use JST.
# However these are time used within the Japanese Military at the time and
# probably does not reflect the time used by local resident at the time (that
# is if they keep their own time back then)
#
# In January 1919 the occupying force issued a command that split the area
# into three different timezone with meridian of 135E, 150E, 165E (JST+0, +1,
# +2), and the command was to become effective from February 1 of the same
# year. Despite the target of the command is still only for the occupying
# force itself, further publication have described the time as the standard
# time for the occupied area and thus it can probably be seen as such.
# * Area that use meridian of 135E: Palau and Yap civil administration area
# (Southern Islands Western Standard Time)
# * Area that use meridian of 150E: Truk (Chuuk) and Saipan civil
# administration area (Southern Islands Central Standard Time)
# * Area that use meridian of 165E: Ponape (Pohnpei) and Jaluit civil
# administration area (Southern Islands Eastern Standard Time).
# * In the next few years Japanese occupation of those islands have been
# formalized via League of Nation Mandate (South Pacific Mandate) and formal
# governance structure have been established, these district [become
# subprefectures] and timezone classification have been inherited as standard
# time of the area.
# * Saipan subprefecture include Mariana islands (exclude Guam which was
# occupied by America at the time), Palau and Yap subprefecture rule the
# Western Caroline Islands with 137E longitude as border, Truk and Ponape
# subprefecture rule the Eastern Caroline Islands with 154E as border, Ponape
# subprefecture also rule part of Marshall Islands to the west of 164E
# starting from (1918?) and Jaluit subprefecture rule the rest of the
# Marshall Islands.
#
# And then in year 1937, an announcement was made to change the time in the
# area into 2 timezones:
# * Area that use meridian of 135E: area administered by Palau, Yap and
# Saipan subprefecture (Southern Islands Western Standard Time)
# * Area that use meridian of 150E: area administered by Truk (Chuuk),
# Ponape (Pohnpei) and Jaluit subprefecture (Southern Islands Eastern
# Standard Time)
#
# Another announcement issued in 1941 say that on April 1 that year,
# standard time of the Southern Islands would be changed to use the meridian
# of 135E (GMT+9), and thus abolishing timezone different within the area.
#
# Then Pacific theater of WWII started and Japan slowly lose control on the
# island. The webpage I linked above contain no information during this
# period of time....
#
# After the end of WWII, in 1946 February, a document written by the
# (former?) Japanese military personnel describe there are 3 hours time
# different between Caroline islands time/Wake island time and the Chungking
# time, which would mean the time being used there at the time was GMT+10.
#
# After that, the area become Trust Territories of the Pacific Islands
# under American administration from year 1947. The site listed some
# American/International books/maps/publications about time used in those
# area during this period of time but they doesn't seems to be reliable
# information so it would be the best if someone know where can more reliable
# information can be found.
#
#
# From Paul Eggert (2018-11-18):
#
# For the above, use vague dates like "1914" and "1945" for transitions that
# plausibly exist but for which the details are not known. The information
# for Wake is too sketchy to act on.
#
# The 1906 GMT+10 info about German-controlled islands might not have been
# done, so omit it from the data for now.
#
# The Jaluit info governs Kwajalein.
# Midway
# From Charles T O'Connor, KMTH DJ (1956),
# quoted in the KTMH section of the Radio Heritage Collection
# <http://radiodx.com/spdxr/KMTH.htm> (2002-12-31):
# For the past two months we've been on what is known as Daylight
# Saving Time. This time has put us on air at 5am in the morning,
# your time down there in New Zealand. Starting September 2, 1956
# we'll again go back to Standard Time. This'll mean that we'll go to
# air at 6am your time.
#
# From Paul Eggert (2003-03-23):
# We don't know the date of that quote, but we'll guess they
# started DST on June 3. Possibly DST was observed other years
# in Midway, but we have no record of it.
# Nauru
# From Phake Nick (2018-10-31):
# Currently, the tz database say Nauru use LMT until 1921, and then
# switched to GMT+11:30 for the next two decades.
# However, a number of timezone map published in America/Japan back then
# showed its timezone as GMT+11 per https://wiki.suikawiki.org/n/ナウルの標準時
# And it would also be nice if the 1921 transition date could be sourced.
# ...
# The "Nauru Standard Time Act 1978 Time Change"
# http://ronlaw.gov.nr/nauru_lpms/files/gazettes/4b23a17d2030150404db7a5fa5872f52.pdf#page=3
# based on "Nauru Standard Time Act 1978 Time Change"
# http://www.paclii.org/nr/legis/num_act/nsta1978207/ defined that "Nauru
# Alternative Time" (GMT+12) should be in effect from 1979 Feb.
#
# From Paul Eggert (2018-11-19):
# The 1921-01-15 introduction of standard time is in Shanks; it is also in
# "Standard Time Throughout the World", US National Bureau of Standards (1935),
# page 3, which does not give the UT offset. In response to a comment by
# Phake Nick I set the Nauru time of occupation by Japan to
# 1942-08-29/1945-09-08 by using dates from:
# https://en.wikipedia.org/wiki/Japanese_occupation_of_Nauru
# Norfolk
# From Alexander Krivenyshev (2015-09-23):
# Norfolk Island will change ... from +1130 to +1100:
# https://www.comlaw.gov.au/Details/F2015L01483/Explanatory%20Statement/Text
# ... at 12.30 am (by legal time in New South Wales) on 4 October 2015.
# http://www.norfolkisland.gov.nf/nia/MediaRelease/Media%20Release%20Norfolk%20Island%20Standard%20Time%20Change.pdf
# From Paul Eggert (2019-08-28):
# Transitions before 2015 are from timeanddate.com, which consulted
# the Norfolk Island Museum and the Australian Bureau of Meteorology's
# Norfolk Island station, and found no record of Norfolk observing DST
# other than in 1974/5. See:
# https://www.timeanddate.com/time/australia/norfolk-island.html
# However, disagree with timeanddate about the 1975-03-02 transition;
# timeanddate has 02:00 but 02:00s corresponds to what the NSW law said
# (thanks to Michael Deckers).
# Norfolk started observing Australian DST in spring 2019.
# From Kyle Czech (2019-08-13):
# https://www.legislation.gov.au/Details/F2018L01702
# From Michael Deckers (2019-08-14):
# https://www.legislation.gov.au/Details/F2019C00010
# Palau
# See commentary for Micronesia.
# Pitcairn
# From Rives McDow (1999-11-08):
# A Proclamation was signed by the Governor of Pitcairn on the 27th March 1998
# with regard to Pitcairn Standard Time. The Proclamation is as follows.
#
# The local time for general purposes in the Islands shall be
# Co-ordinated Universal time minus 8 hours and shall be known
# as Pitcairn Standard Time.
#
# ... I have also seen Pitcairn listed as UTC minus 9 hours in several
# references, and can only assume that this was an error in interpretation
# somehow in light of this proclamation.
# From Rives McDow (1999-11-09):
# The Proclamation regarding Pitcairn time came into effect on 27 April 1998
# ... at midnight.
# From Howie Phelps (1999-11-10), who talked to a Pitcairner via shortwave:
# Betty Christian told me yesterday that their local time is the same as
# Pacific Standard Time. They used to be ½ hour different from us here in
# Sacramento but it was changed a couple of years ago.
# (Western) Samoa and American Samoa
# Howse writes (p 153) that after the 1879 standardization on Antipodean
# time by the British governor of Fiji, the King of Samoa decided to change
# "the date in his kingdom from the Antipodean to the American system,
# ordaining - by a masterpiece of diplomatic flattery - that
# the Fourth of July should be celebrated twice in that year."
# This happened in 1892, according to the Evening News (Sydney) of 1892-07-20.
# https://www.staff.science.uu.nl/~gent0113/idl/idl.htm
# Although Shanks & Pottenger says they both switched to UT -11:30
# in 1911, and to -11 in 1950. many earlier sources give -11
# for American Samoa, e.g., the US National Bureau of Standards
# circular "Standard Time Throughout the World", 1932.
# Assume American Samoa switched to -11 in 1911, not 1950,
# and that after 1950 they agreed until (western) Samoa skipped a
# day in 2011. Assume also that the Samoas follow the US and New
# Zealand's "ST"/"DT" style of daylight-saving abbreviations.
# Tonga
# From Paul Eggert (1996-01-22):
# Today's _Wall Street Journal_ (p 1) reports that "Tonga has been plotting
# to sneak ahead of [New Zealanders] by introducing daylight-saving time."
# Since Kiribati has moved the Date Line it's not clear what Tonga will do.
# Don Mundell writes in the 1997-02-20 Tonga Chronicle
# How Tonga became 'The Land where Time Begins':
# http://www.tongatapu.net.to/tonga/homeland/timebegins.htm
#
# Until 1941 Tonga maintained a standard time 50 minutes ahead of NZST
# 12 hours and 20 minutes ahead of GMT. When New Zealand adjusted its
# standard time in 1940s, Tonga had the choice of subtracting from its
# local time to come on the same standard time as New Zealand or of
# advancing its time to maintain the differential of 13°
# (approximately 50 minutes ahead of New Zealand time).
#
# Because His Majesty King Tāufaʻāhau Tupou IV, then Crown Prince
# Tungī, preferred to ensure Tonga's title as the land where time
# begins, the Legislative Assembly approved the latter change.
#
# But some of the older, more conservative members from the outer
# islands objected. "If at midnight on Dec. 31, we move ahead 40
# minutes, as your Royal Highness wishes, what becomes of the 40
# minutes we have lost?"
#
# The Crown Prince, presented an unanswerable argument: "Remember that
# on the World Day of Prayer, you would be the first people on Earth
# to say your prayers in the morning."
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say the transition was on 1968-10-01; go with Mundell.
# From Eric Ulevik (1999-05-03):
# Tonga's director of tourism, who is also secretary of the National Millennium
# Committee, has a plan to get Tonga back in front.
# He has proposed a one-off move to tropical daylight saving for Tonga from
# October to March, which has won approval in principle from the Tongan
# Government.
# From Steffen Thorsen (1999-09-09):
# * Tonga will introduce DST in November
#
# I was given this link by John Letts:
# http://news.bbc.co.uk/hi/english/world/asia-pacific/newsid_424000/424764.stm
#
# I have not been able to find exact dates for the transition in November
# yet. By reading this article it seems like Fiji will be 14 hours ahead
# of UTC as well, but as far as I know Fiji will only be 13 hours ahead
# (12 + 1 hour DST).
# From Arthur David Olson (1999-09-20):
# According to <http://www.tongaonline.com/news/sept1799.html>:
# "Daylight Savings Time will take effect on Oct. 2 through April 15, 2000
# and annually thereafter from the first Saturday in October through the
# third Saturday of April. Under the system approved by Privy Council on
# Sept. 10, clocks must be turned ahead one hour on the opening day and
# set back an hour on the closing date."
# Alas, no indication of the time of day.
# From Rives McDow (1999-10-06):
# Tonga started its Daylight Saving on Saturday morning October 2nd at 0200am.
# Daylight Saving ends on April 16 at 0300am which is Sunday morning.
# From Steffen Thorsen (2000-10-31):
# Back in March I found a notice on the website http://www.tongaonline.com
# that Tonga changed back to standard time one month early, on March 19
# instead of the original reported date April 16. Unfortunately, the article
# is no longer available on the site, and I did not make a copy of the
# text, and I have forgotten to report it here.
# (Original URL was <http://www.tongaonline.com/news/march162000.htm>)
# From Rives McDow (2000-12-01):
# Tonga is observing DST as of 2000-11-04 and will stop on 2001-01-27.
# From Sione Moala-Mafi (2001-09-20) via Rives McDow:
# At 2:00am on the first Sunday of November, the standard time in the Kingdom
# shall be moved forward by one hour to 3:00am. At 2:00am on the last Sunday
# of January the standard time in the Kingdom shall be moved backward by one
# hour to 1:00am.
# From Pulu ʻAnau (2002-11-05):
# The law was for 3 years, supposedly to get renewed. It wasn't.
# From Pulu ʻAnau (2016-10-27):
# http://mic.gov.to/news-today/press-releases/6375-daylight-saving-set-to-run-from-6-november-2016-to-15-january-2017
# Cannot find anyone who knows the rules, has seen the duration or has seen
# the cabinet decision, but it appears we are following Fiji's rule set.
#
# From Tim Parenti (2016-10-26):
# Assume Tonga will observe DST from the first Sunday in November at 02:00
# through the third Sunday in January at 03:00, like Fiji, for now.
# From David Wade (2017-10-18):
# In August government was disolved by the King. The current prime minister
# continued in office in care taker mode. It is easy to see that few
# decisions will be made until elections 16th November.
#
# From Paul Eggert (2017-10-18):
# For now, guess that DST is discontinued. That's what the IATA is guessing.
# Wake
# From Vernice Anderson, Personal Secretary to Philip Jessup,
# US Ambassador At Large (oral history interview, 1971-02-02):
#
# Saturday, the 14th [of October, 1950] - ... The time was all the
# more confusing at that point, because we had crossed the
# International Date Line, thus getting two Sundays. Furthermore, we
# discovered that Wake Island had two hours of daylight saving time
# making calculation of time in Washington difficult if not almost
# impossible.
#
# https://www.trumanlibrary.org/oralhist/andrsonv.htm
# From Paul Eggert (2003-03-23):
# We have no other report of DST in Wake Island, so omit this info for now.
# See also the commentary for Micronesia.
###############################################################################
# The International Date Line
# From Gwillim Law (2000-01-03):
#
# The International Date Line is not defined by any international standard,
# convention, or treaty. Mapmakers are free to draw it as they please.
# Reputable mapmakers will simply ensure that every point of land appears on
# the correct side of the IDL, according to the date legally observed there.
#
# When Kiribati adopted a uniform date in 1995, thereby moving the Phoenix and
# Line Islands to the west side of the IDL (or, if you prefer, moving the IDL
# to the east side of the Phoenix and Line Islands), I suppose that most
# mapmakers redrew the IDL following the boundary of Kiribati. Even that line
# has a rather arbitrary nature. The straight-line boundaries between Pacific
# island nations that are shown on many maps are based on an international
# convention, but are not legally binding national borders.... The date is
# governed by the IDL; therefore, even on the high seas, there may be some
# places as late as fourteen hours later than UTC. And, since the IDL is not
# an international standard, there are some places on the high seas where the
# correct date is ambiguous.
# From Wikipedia <https://en.wikipedia.org/wiki/Time_zone> (2005-08-31):
# Before 1920, all ships kept local apparent time on the high seas by setting
# their clocks at night or at the morning sight so that, given the ship's
# speed and direction, it would be 12 o'clock when the Sun crossed the ship's
# meridian (12 o'clock = local apparent noon). During 1917, at the
# Anglo-French Conference on Time-keeping at Sea, it was recommended that all
# ships, both military and civilian, should adopt hourly standard time zones
# on the high seas. Whenever a ship was within the territorial waters of any
# nation it would use that nation's standard time. The captain was permitted
# to change his ship's clocks at a time of his choice following his ship's
# entry into another zone time - he often chose midnight. These zones were
# adopted by all major fleets between 1920 and 1925 but not by many
# independent merchant ships until World War II.
# From Paul Eggert, using references suggested by Oscar van Vlijmen
# (2005-03-20):
#
# The American Practical Navigator (2002)
# http://pollux.nss.nima.mil/pubs/pubs_j_apn_sections.html?rid=187
# talks only about the 180-degree meridian with respect to ships in
# international waters; it ignores the international date line.