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# tzdb data for North and Central America and environs

# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.

# also includes Central America and the Caribbean

# 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
# the public mailing list tz@iana.org for general use in the future.
# For more, please see the file CONTRIBUTING in the tz distribution.

# From Paul Eggert (1999-03-22):
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).

###############################################################################

# United States

# From Paul Eggert (1999-03-31):
# Howse writes (pp 121-125) that time zones were invented by
# Professor Charles Ferdinand Dowd (1825-1904),
# Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
# His pamphlet "A System of National Time for Railroads" (1870)
# was the result of his proposals at the Convention of Railroad Trunk Lines
# in New York City (1869-10).  His 1870 proposal was based on Washington, DC,
# but in 1872-05 he moved the proposed origin to Greenwich.

# From Paul Eggert (2024-11-18):
# Dowd's proposal left many details unresolved, such as where to draw
# lines between time zones.  Sandford Fleming of the Canadian Pacific Railway
# argued for Dowd's proposal in 1876, and Cleveland Abbe of the American
# Meteorology Society published a report in 1879 recommending four US time
# zones based on GMT.  However, the key individual who made time zones
# work in the US was William Frederick Allen - railway engineer,
# managing editor of the Travelers' Guide, and secretary of the
# General Time Convention, a railway standardization group.  Allen
# spent months in dialogs with scientific and railway leaders,
# developed a workable plan to institute time zones, and presented it
# to the General Time Convention on 1883-04-11, saying that his plan
# meant "local time would be practically abolished" - a plus for
# railway scheduling.  By the next convention on 1883-10-11 nearly all
# railroads had agreed and it took effect on 1883-11-18.  That Sunday
# was called the "day of two noons", as some locations observed noon
# twice.  Allen witnessed the transition in New York City, writing:
#
#   I heard the bells of St. Paul's strike on the old time.  Four
#   minutes later, obedient to the electrical signal from the Naval
#   Observatory ... the time-ball made its rapid descent, the chimes
#   of old Trinity rang twelve measured strokes, and local time was
#   abandoned, probably forever.
#
# Most of the US soon followed suit.  See:
# Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
# https://dx.doi.org/10.2307/3105430

# From Paul Eggert (2005-04-16):
# That 1883 transition occurred at 12:00 new time, not at 12:00 old time.
# See p 46 of David Prerau, Seize the daylight, Thunder's Mouth Press (2005).

# From Paul Eggert (2006-03-22):
# A good source for time zone historical data in the US is
# Thomas G. Shanks, The American Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1991).
# Make sure you have the errata sheet; the book is somewhat useless without it.
# It is the source for most of the pre-1991 US entries below.

# From Paul Eggert (2001-03-06):
# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
# in his whimsical essay "An Economical Project for Diminishing the Cost
# of Light" published in the Journal de Paris (1784-04-26).
# Not everyone is happy with the results:
#
#	I don't really care how time is reckoned so long as there is some
#	agreement about it, but I object to being told that I am saving
#	daylight when my reason tells me that I am doing nothing of the kind.
#	I even object to the implication that I am wasting something
#	valuable if I stay in bed after the sun has risen.  As an admirer
#	of moonlight I resent the bossy insistence of those who want to
#	reduce my time for enjoying it.  At the back of the Daylight Saving
#	scheme I detect the bony, blue-fingered hand of Puritanism, eager
#	to push people into bed earlier, and get them up earlier, to make
#	them healthy, wealthy and wise in spite of themselves.
#
#	 -- Robertson Davies, The diary of Samuel Marchbanks,
#	   Clarke, Irwin (1947), XIX, Sunday
#
# For more about the first ten years of DST in the United States, see
# Robert Garland, Ten years of daylight saving from the Pittsburgh standpoint
# (Carnegie Library of Pittsburgh, 1927).
# https://web.archive.org/web/20160517155308/http://www.clpgh.org/exhibit/dst.html
#
# Shanks says that DST was called "War Time" in the US in 1918 and 1919.
# However, DST was imposed by the Standard Time Act of 1918, which
# was the first nationwide legal time standard, and apparently
# time was just called "Standard Time" or "Daylight Saving Time".

# From Paul Eggert (2019-06-04):
# Here is the legal basis for the US federal rules.
# * Public Law 65-106 (1918-03-19) implemented standard and daylight saving
#   time for the first time across the US, springing forward on March's last
#   Sunday and falling back on October's last Sunday.
#   https://www.loc.gov/law/help/statutes-at-large/65th-congress/session-2/c65s2ch24.pdf
# * Public Law 66-40 (1919-08-20) repealed DST on October 1919's last Sunday.
#   https://www.loc.gov/law/help/statutes-at-large/66th-congress/session-1/c66s1ch51.pdf
# * Public Law 77-403 (1942-01-20) started wartime DST on 1942-02-09.
#   https://www.loc.gov/law/help/statutes-at-large/77th-congress/session-2/c77s2ch7.pdf
# * Public Law 79-187 (1945-09-25) ended wartime DST on 1945-09-30.
#   https://www.loc.gov/law/help/statutes-at-large/79th-congress/session-1/c79s1ch388.pdf
# * Public Law 89-387 (1966-04-13) reinstituted a national standard for DST,
#   from April's last Sunday to October's last Sunday, effective 1967.
#   https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
# * Public Law 93-182 (1973-12-15) moved the 1974 spring-forward to 01-06.
#   https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
# * Public Law 93-434 (1974-10-05) moved the 1975 spring-forward to
#   February's last Sunday.
#   https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
# * Public Law 99-359 (1986-07-08) moved the spring-forward to April's first
#   Sunday.
#   https://www.govinfo.gov/content/pkg/STATUTE-100/pdf/STATUTE-100-Pg764.pdf
# * Public Law 109-58 (2005-08-08), effective 2007, moved the spring-forward
#   to March's second Sunday and the fall-back to November's first Sunday.
#   https://www.govinfo.gov/content/pkg/PLAW-109publ58/pdf/PLAW-109publ58.pdf
# All transitions are at 02:00 local time.

# From Arthur David Olson:
# Before the Uniform Time Act of 1966 took effect in 1967, observance of
# Daylight Saving Time in the US was by local option, except during wartime.

# From Arthur David Olson (2000-09-25):
# Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
# In the introduction, Oboler spoke of "Eastern Peace Time."
# An AltaVista search turned up:
# https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
# "When the time is announced over the radio now, it is 'Eastern Peace
# Time' instead of the old familiar 'Eastern War Time.'  Peace is wonderful."
# (August 1945) by way of confirmation.
#
# From Paul Eggert (2017-09-23):
# This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.

# From Joseph Gallant citing
# George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
# At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
# to switch to London for Attlee's address, but the American people
# never got to hear his speech live. According to one press account,
# CBS' Bob Trout was first to announce the word of Japan's surrender,
# but a few seconds later, NBC, ABC and Mutual also flashed the word
# of surrender, all of whom interrupting the bells of Big Ben in
# London which were to precede Mr. Attlee's speech.

# From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout.  From
# Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
#
# ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
# Any announcement from Asia would reach St. John's New York newsroom on a
# wire service teletype machine, which had prescribed signals for major news.
# Associated Press, for example, would ring five bells before spewing out
# typed copy of an important story, and 10 bells for news "of transcendental
# importance."
#
# On Aug. 14, stalling while talking steadily into the NBC networks' open
# microphone, St. John heard five bells and waited only to hear a sixth bell,
# before announcing confidently: "Ladies and gentlemen, World War II is over.
# The Japanese have agreed to our surrender terms."
#
# He had scored a 20-second scoop on other broadcasters.

# From Arthur David Olson (2005-08-22):
# Paul has been careful to use the "US" rules only in those locations
# that are part of the United States; this reflects the real scope of
# U.S. government action.  So even though the "US" rules have changed
# in the latest release, other countries won't be affected.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	US	1918	1919	-	Mar	lastSun	2:00	1:00	D
Rule	US	1918	1919	-	Oct	lastSun	2:00	0	S
Rule	US	1942	only	-	Feb	9	2:00	1:00	W # War
Rule	US	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	US	1945	only	-	Sep	30	2:00	0	S
Rule	US	1967	2006	-	Oct	lastSun	2:00	0	S
Rule	US	1967	1973	-	Apr	lastSun	2:00	1:00	D
Rule	US	1974	only	-	Jan	6	2:00	1:00	D
Rule	US	1975	only	-	Feb	lastSun	2:00	1:00	D
Rule	US	1976	1986	-	Apr	lastSun	2:00	1:00	D
Rule	US	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
Rule	US	2007	max	-	Mar	Sun>=8	2:00	1:00	D
Rule	US	2007	max	-	Nov	Sun>=1	2:00	0	S

# From U. S. Naval Observatory (1989-01-19):
# USA  EASTERN       5 H  BEHIND UTC    NEW YORK, WASHINGTON
# USA  EASTERN       4 H  BEHIND UTC    APR 3 - OCT 30
# USA  CENTRAL       6 H  BEHIND UTC    CHICAGO, HOUSTON
# USA  CENTRAL       5 H  BEHIND UTC    APR 3 - OCT 30
# USA  MOUNTAIN      7 H  BEHIND UTC    DENVER
# USA  MOUNTAIN      6 H  BEHIND UTC    APR 3 - OCT 30
# USA  PACIFIC       8 H  BEHIND UTC    L.A., SAN FRANCISCO
# USA  PACIFIC       7 H  BEHIND UTC    APR 3 - OCT 30
# USA  ALASKA STD    9 H  BEHIND UTC    MOST OF ALASKA     (AKST)
# USA  ALASKA STD    8 H  BEHIND UTC    APR 3 - OCT 30 (AKDT)
# USA  ALEUTIAN     10 H  BEHIND UTC    ISLANDS WEST OF 170W
# USA    "           9 H  BEHIND UTC    APR 3 - OCT 30
# USA  HAWAII       10 H  BEHIND UTC
# USA  BERING       11 H  BEHIND UTC    SAMOA, MIDWAY

# From Arthur David Olson (1989-01-21):
# The above dates are for 1988.
# Note the "AKST" and "AKDT" abbreviations, the claim that there's
# no DST in Samoa, and the claim that there is DST in Alaska and the
# Aleutians.

# From Arthur David Olson (1988-02-13):
# Legal standard time zone names, from United States Code (1982 Edition and
# Supplement III), Title 15, Chapter 6, Section 260 and forward.  First, names
# up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
# took effect), as explained in sections 263 and 261:
#	(none)
#	United States standard eastern time
#	United States standard mountain time
#	United States standard central time
#	United States standard Pacific time
#	(none)
#	United States standard Alaska time
#	(none)
# Next, names from 1967-04-01 until 1983-11-30 (the date for
# public law 98-181):
#	Atlantic standard time
#	eastern standard time
#	central standard time
#	mountain standard time
#	Pacific standard time
#	Yukon standard time
#	Alaska-Hawaii standard time
#	Bering standard time
# And after 1983-11-30:
#	Atlantic standard time
#	eastern standard time
#	central standard time
#	mountain standard time
#	Pacific standard time
#	Alaska standard time
#	Hawaii-Aleutian standard time
#	Samoa standard time
# The law doesn't give abbreviations.
#
# From Paul Eggert (2016-12-19):
# Here are URLs for the 1918 and 1966 legislation:
# http://uscode.house.gov/statviewer.htm?volume=40&page=451
# http://uscode.house.gov/statviewer.htm?volume=80&page=108
# Although the 1918 names were officially "United States Standard
# Eastern Time" and similarly for "Central", "Mountain", "Pacific",
# and "Alaska", in practice "Standard" was placed just before "Time",
# as codified in 1966.  In practice, Alaska time was abbreviated "AST"
# before 1968.  Summarizing the 1967 name changes:
#	1918 names			1967 names
#  -08	Standard Pacific Time (PST)	Pacific standard time (PST)
#  -09	(unofficial) Yukon (YST)	Yukon standard time (YST)
#  -10	Standard Alaska Time (AST)	Alaska-Hawaii standard time (AHST)
#  -11	(unofficial) Nome (NST)		Bering standard time (BST)
#
# From Paul Eggert (2023-01-23), from a 2001-01-08 heads-up from Rives McDow:
# Public law 106-564 (2000-12-23) introduced "Chamorro standard time"
# for time in Guam and the Northern Marianas.  See the file "australasia".
# Also see 15 U.S.C. §263 <https://www.law.cornell.edu/uscode/text/15/263>.
#
# From Paul Eggert (2015-04-17):
# HST and HDT are standardized abbreviations for Hawaii-Aleutian
# standard and daylight times.  See section 9.47 (p 234) of the
# U.S. Government Printing Office Style Manual (2008)
# https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf

# From Arthur David Olson, 2005-08-09
# The following was signed into law on 2005-08-08.
#
# H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS.
#   (a) Amendment.--Section 3(a) of the Uniform Time Act of 1966 (15
#   U.S.C. 260a(a)) is amended--
#     (1) by striking "first Sunday of April" and inserting "second
#     Sunday of March"; and
#     (2) by striking "last Sunday of October" and inserting "first
#     Sunday of November'.
#   (b) Effective Date.--Subsection (a) shall take effect 1 year after the
#   date of enactment of this Act or March 1, 2007, whichever is later.
#   (c) Report to Congress.--Not later than 9 months after the effective
#   date stated in subsection (b), the Secretary shall report to Congress
#   on the impact of this section on energy consumption in the United
#   States.
#   (d) Right to Revert.--Congress retains the right to revert the
#   Daylight Saving Time back to the 2005 time schedules once the
#   Department study is complete.

# US eastern time, represented by New York

# Connecticut, Delaware, District of Columbia, most of Florida,
# Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky
# (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts,
# New Hampshire, New Jersey, New York, North Carolina, Ohio,
# Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
# Vermont, Virginia, West Virginia

# From Dave Cantor (2004-11-02):
# Early this summer I had the occasion to visit the Mount Washington
# Observatory weather station atop (of course!) Mount Washington [, NH]....
# One of the staff members said that the station was on Eastern Standard Time
# and didn't change their clocks for Daylight Saving ... so that their
# reports will always have times which are 5 hours behind UTC.

# From Paul Eggert (2005-08-26):
# According to today's Huntsville Times
# http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/1125047783228320.xml&coll=1
# a few towns on Alabama's "eastern border with Georgia, such as Phenix City
# in Russell County, Lanett in Chambers County and some towns in Lee County,
# set their watches and clocks on Eastern time."  It quotes H.H. "Bubba"
# Roberts, city administrator in Phenix City. as saying "We are in the Central
# time zone, but we do go by the Eastern time zone because so many people work
# in Columbus."
#
# From Paul Eggert (2017-02-22):
# Four cities are involved.  The two not mentioned above are Smiths Station
# and Valley.  Barbara Brooks, Valley's assistant treasurer, heard it started
# because West Point Pepperell textile mills were in Alabama while the
# corporate office was in Georgia, and residents voted to keep Eastern
# time even after the mills closed.  See: Kazek K. Did you know which
# Alabama towns are in a different time zone?  al.com 2017-02-06.
# http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html

# From Paul Eggert (2014-09-06):
# Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
# says that New York City Hall time was 3 minutes 58.4 seconds fast of
# Eastern time (i.e., -4:56:01.6) just before the 1883 switch.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	NYC	1920	only	-	Mar	lastSun	2:00	1:00	D
Rule	NYC	1920	only	-	Oct	lastSun	2:00	0	S
Rule	NYC	1921	1966	-	Apr	lastSun	2:00	1:00	D
Rule	NYC	1921	1954	-	Sep	lastSun	2:00	0	S
Rule	NYC	1955	1966	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
		#STDOFF	-4:56:01.6
Zone America/New_York	-4:56:02 -	LMT	1883 Nov 18 17:00u
			-5:00	US	E%sT	1920
			-5:00	NYC	E%sT	1942
			-5:00	US	E%sT	1946
			-5:00	NYC	E%sT	1967
			-5:00	US	E%sT

# US central time, represented by Chicago

# Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
# Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
# Washington counties), Illinois, western Indiana
# (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
# Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
# Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
# Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
# western Tennessee, most of Texas, Wisconsin

# From Paul Eggert (2018-01-07):
# In 1869 the Chicago Astronomical Society contracted with the city to keep
# time.  Though delayed by the Great Fire, by 1880 a wire ran from the
# Dearborn Observatory (on the University of Chicago campus) to City Hall,
# which then sent signals to police and fire stations.  However, railroads got
# their time signals from the Allegheny Observatory, the Madison Observatory,
# the Ann Arbor Observatory, etc., so their clocks did not agree with each
# other or with the city's official time.  The confusion took some years to
# clear up.  See:
# Moser M. How Chicago gave America its time zones. Chicago. 2018-01-04.
# http://www.chicagomag.com/city-life/January-2018/How-Chicago-Gave-America-Its-Time-Zones/

# From Larry M. Smith (2006-04-26) re Wisconsin:
# https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
# is currently enforced at the 01:00 time of change.  Because the local
# "bar time" in the state corresponds to 02:00, a number of citations
# are issued for the "sale of class 'B' alcohol after prohibited
# hours" within the deviated hour of this change every year....
#
# From Douglas R. Bomberg (2007-03-12):
# Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
# Statue 175 closer in synch with the US Congress' intent....
# https://docs.legis.wisconsin.gov/2007/related/acts/3

# From an email administrator of the City of Fort Pierre, SD (2015-12-21):
# Fort Pierre is technically located in the Mountain time zone as is
# the rest of Stanley County.  Most of Stanley County and Fort Pierre
# uses the Central time zone due to doing most of their business in
# Pierre so it simplifies schedules.  I have lived in Stanley County
# all my life and it has been that way since I can remember.  (43 years!)
#
# From Paul Eggert (2015-12-25):
# Assume this practice predates 1970, so Fort Pierre can use America/Chicago.

# From Paul Eggert (2015-04-06):
# In 1950s Nashville a public clock had dueling faces, one for conservatives
# and the other for liberals; the two sides didn't agree about the time of day.
# I haven't found a photo of this clock, nor have I tracked down the TIME
# magazine report cited below, but here's the story as told by the late
# American journalist John Seigenthaler, who was there:
#
# "The two [newspaper] owners held strongly contrasting political and
# ideological views.  Evans was a New South liberal, Stahlman an Old South
# conservative, and their two papers frequently clashed editorially, often on
# the same day....  In the 1950s as the state legislature was grappling with
# the question of whether to approve daylight saving time for the entire state,
# TIME magazine reported:
#
# "'The Nashville Banner and The Nashville Tennessean rarely agree on anything
# but the time of day - and last week they couldn't agree on that.'
#
# "It was all too true. The clock on the front of the building had two faces -
# The Tennessean side of the building facing west, the other, east.  When it
# was high noon Banner time, it was 11 a.m. Tennessean time."
#
# Seigenthaler J. For 100 years, Tennessean had it covered.
# The Tennessean 2007-05-11, republished 2015-04-06.
# https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Chicago	1920	only	-	Jun	13	2:00	1:00	D
Rule	Chicago	1920	1921	-	Oct	lastSun	2:00	0	S
Rule	Chicago	1921	only	-	Mar	lastSun	2:00	1:00	D
Rule	Chicago	1922	1966	-	Apr	lastSun	2:00	1:00	D
Rule	Chicago	1922	1954	-	Sep	lastSun	2:00	0	S
Rule	Chicago	1955	1966	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Chicago	-5:50:36 -	LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1920
			-6:00	Chicago	C%sT	1936 Mar  1  2:00
			-5:00	-	EST	1936 Nov 15  2:00
			-6:00	Chicago	C%sT	1942
			-6:00	US	C%sT	1946
			-6:00	Chicago	C%sT	1967
			-6:00	US	C%sT
# Oliver County, ND switched from mountain to central time on 1992-10-25.
Zone America/North_Dakota/Center -6:45:12 - LMT	1883 Nov 18 19:00u
			-7:00	US	M%sT	1992 Oct 25  2:00
			-6:00	US	C%sT
# Morton County, ND, switched from mountain to central time on
# 2003-10-26, except for the area around Mandan which was already central time.
# See <http://dmses.dot.gov/docimages/p63/135818.pdf>.
# Officially this switch also included part of Sioux County, and
# Jones, Mellette, and Todd Counties in South Dakota;
# but in practice these other counties were already observing central time.
# See <http://www.epa.gov/fedrgstr/EPA-IMPACT/2003/October/Day-28/i27056.htm>.
Zone America/North_Dakota/New_Salem -6:45:39 - LMT 1883 Nov 18 19:00u
			-7:00	US	M%sT	2003 Oct 26  2:00
			-6:00	US	C%sT

# From Josh Findley (2011-01-21):
# ...it appears that Mercer County, North Dakota, changed from the
# mountain time zone to the central time zone at the last transition from
# daylight-saving to standard time (on Nov. 7, 2010):
# https://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
# http://www.bismarcktribune.com/news/local/article_1eb1b588-c758-11df-b472-001cc4c03286.html

# From Andy Lipscomb (2011-01-24):
# ...according to the Census Bureau, the largest city is Beulah (although
# it's commonly referred to as Beulah-Hazen, with Hazen being the next
# largest city in Mercer County).  Google Maps places Beulah's city hall
# at 47° 15' 51" N, 101° 46' 40" W, which yields an offset of 6h47'07".

Zone America/North_Dakota/Beulah -6:47:07 - LMT	1883 Nov 18 19:00u
			-7:00	US	M%sT	2010 Nov  7  2:00
			-6:00	US	C%sT

# US mountain time, represented by Denver
#
# Colorado, far western Kansas, Montana, western
# Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
# New Mexico, southwestern North Dakota,
# western South Dakota, far western Texas (El Paso County, Hudspeth County,
# and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
#
# From Paul Eggert (2018-10-25):
# On 1921-03-04 federal law placed all of Texas into the central time zone.
# However, El Paso ignored the law for decades and continued to observe
# mountain time, on the grounds that that's what they had always done
# and they weren't about to let the federal government tell them what to do.
# Eventually the federal government gave in and changed the law on
# 1970-04-10 to match what El Paso was actually doing.  Although
# that's slightly after our 1970 cutoff, there is no need to create a
# separate zone for El Paso since they were ignoring the law anyway.  See:
# Long T. El Pasoans were time rebels, fought to stay in Mountain zone.
# El Paso Times. 2018-10-24 06:40 -06.
# https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/
#
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Denver	1920	1921	-	Mar	lastSun	2:00	1:00	D
Rule	Denver	1920	only	-	Oct	lastSun	2:00	0	S
Rule	Denver	1921	only	-	May	22	2:00	0	S
Rule	Denver	1965	1966	-	Apr	lastSun	2:00	1:00	D
Rule	Denver	1965	1966	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Denver	-6:59:56 -	LMT	1883 Nov 18 19:00u
			-7:00	US	M%sT	1920
			-7:00	Denver	M%sT	1942
			-7:00	US	M%sT	1946
			-7:00	Denver	M%sT	1967
			-7:00	US	M%sT

# US Pacific time, represented by Los Angeles
#
# California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
# Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties, Idaho county
# north of the Salmon River, and the towns of Burgdorf and Warren),
# Nevada (except West Wendover), Oregon (except the northern ¾ of
# Malheur county), and Washington

# From Paul Eggert (2016-08-20):
# In early February 1948, in response to California's electricity shortage,
# PG&E changed power frequency from 60 to 59.5 Hz during daylight hours,
# causing electric clocks to lose six minutes per day.  (This did not change
# legal time, and is not part of the data here.)  See:
# Ross SA. An energy crisis from the past: Northern California in 1948.
# Working Paper No. 8, Institute of Governmental Studies, UC Berkeley,
# 1973-11.  https://escholarship.org/uc/item/8x22k30c
#
# In another measure to save electricity, DST was instituted from 1948-03-14
# at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move
# the fallback transition earlier.  See pages 3-4 of:
# http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statutes/1948/48Vol1_Chapters.pdf
#
# In response:
#
#   Governor Warren received a torrent of objecting mail, and it is not too much
#   to speculate that the objections to Daylight Saving Time were one important
#   factor in the defeat of the Dewey-Warren Presidential ticket in California.
#     -- Ross, p 25
#
# On December 8 the governor exercised the option, setting the date to January 1
# (LA Times 1948-12-09).  The transition time was 02:00 (LA Times 1949-01-01).
#
# Despite the controversy, in 1949 California voters approved Proposition 12,
# which established DST from April's last Sunday at 01:00 until September's
# last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed
# the fall-back date to October's last Sunday. See:
# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
#
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	CA	1948	only	-	Mar	14	2:01	1:00	D
Rule	CA	1949	only	-	Jan	 1	2:00	0	S
Rule	CA	1950	1966	-	Apr	lastSun	1:00	1:00	D
Rule	CA	1950	1961	-	Sep	lastSun	2:00	0	S
Rule	CA	1962	1966	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Los_Angeles -7:52:58 -	LMT	1883 Nov 18 20:00u
			-8:00	US	P%sT	1946
			-8:00	CA	P%sT	1967
			-8:00	US	P%sT

# Alaska
# AK%sT is the modern abbreviation for -09 per USNO.
#
# From Paul Eggert (2017-06-15):
# Howse writes that Alaska switched from the Julian to the Gregorian calendar,
# and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
# On Friday, 1867-10-18 (Gregorian), at precisely 15:30 local time, the
# Russian forts and fleet at Sitka fired salutes to mark the ceremony of
# formal transfer.  See the Sacramento Daily Union (1867-11-14), p 3, col 2.
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18671114.2.12.1
# Sitka workers did not change their calendars until Sunday, 1867-10-20,
# and so celebrated two Sundays that week.  See: Ahllund T (tr Hallamaa P).
# From the memoirs of a Finnish workman. Alaska History. 2006 Fall;21(2):1-25.
# http://alaskahistoricalsociety.org/wp-content/uploads/2016/12/Ahllund-2006-Memoirs-of-a-Finnish-Workman.pdf
# Include only the time zone part of this transition, ignoring the switch
# from Julian to Gregorian, since we can't represent the Julian calendar.
#
# As far as we know, of the locations mentioned below only Sitka was
# permanently inhabited in 1867 by anyone using either calendar.
# (Yakutat was colonized by the Russians in 1799, but the settlement was
# destroyed in 1805 by a Yakutat-kon war party.)  Many of Alaska's inhabitants
# were unaware of the US acquisition of Alaska, much less of any calendar or
# time change.  However, the Russian-influenced part of Alaska did observe
# Russian time, and it is more accurate to model this than to ignore it.
# The database format requires an exact transition time; use the Russian
# salute as a somewhat-arbitrary time for the formal transfer of control for
# all of Alaska.  Sitka's UTC offset is -9:01:13; adjust its 15:30 to the
# local times of other Alaskan locations so that they change simultaneously.

# From Paul Eggert (2014-07-18):
# One opinion of the early 1980s turmoil in Alaska over time zones and
# daylight saving time appeared as graffiti on a Juneau airport wall:
# "Welcome to Juneau.  Please turn your watch back to the 19th century."
# See: Turner W. Alaska's four time zones now two. NY Times 1983-11-01.
# http://www.nytimes.com/1983/11/01/us/alaska-s-four-time-zones-now-two.html
#
# Steve Ferguson (2011-01-31) referred to the following source:
# Norris F. Keeping time in Alaska: national directives, local response.
# Alaska History 2001;16(1-2).
# http://alaskahistoricalsociety.org/discover-alaska/glimpses-of-the-past/keeping-time-in-alaska/

# From Arthur David Olson (2011-02-01):
# Here's database-relevant material from the 2001 "Alaska History" article:
#
# On September 20 [1979]...DOT...officials decreed that on April 27,
# 1980, Juneau and other nearby communities would move to Yukon Time.
# Sitka, Petersburg, Wrangell, and Ketchikan, however, would remain on
# Pacific Time.
#
# ...on September 22, 1980, DOT Secretary Neil E. Goldschmidt rescinded the
# Department's September 1979 decision. Juneau and other communities in
# northern Southeast reverted to Pacific Time on October 26.
#
# On October 28 [1983]...the Metlakatla Indian Community Council voted
# unanimously to keep the reservation on Pacific Time.
#
# According to DOT official Joanne Petrie, Indian reservations are not
# bound to follow time zones imposed by neighboring jurisdictions.
#
# (The last is consistent with how the database now handles the Navajo
# Nation.)

# From Arthur David Olson (2011-02-09):
# I just spoke by phone with a staff member at the Metlakatla Indian
# Community office (using contact information available at
# http://www.commerce.state.ak.us/dca/commdb/CIS.cfm?Comm_Boro_name=Metlakatla
# It's shortly after 1:00 here on the east coast of the United States;
# the staffer said it was shortly after 10:00 there. When I asked whether
# that meant they were on Pacific time, they said no - they were on their
# own time. I asked about daylight saving; they said it wasn't used. I
# did not inquire about practices in the past.

# From Arthur David Olson (2011-08-17):
# For lack of better information, assume that Metlakatla's
# abandonment of use of daylight saving resulted from the 1983 vote.

# From Steffen Thorsen (2015-11-09):
# It seems Metlakatla did go off PST on Sunday, November 1, changing
# their time to AKST and are going to follow Alaska's DST, switching
# between AKST and AKDT from now on....
# https://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/

# From Ryan Stanley (2018-11-06):
# The Metlakatla community in Alaska has decided not to change its
# clock back an hour starting on November 4th, 2018 (day before yesterday).
# They will be gmtoff=-28800 year-round.
# https://www.facebook.com/141055983004923/photos/pb.141055983004923.-2207520000.1541465673./569081370202380/

# From Paul Eggert (2018-12-16):
# In a 2018-12-11 special election, Metlakatla voted to go back to
# Alaska time (including daylight saving time) starting next year.
# https://www.krbd.org/2018/12/12/metlakatla-to-follow-alaska-standard-time-allow-liquor-sales/
#
# From Ryan Stanley (2019-01-11):
# The community will be changing back on the 20th of this month...
# From Tim Parenti (2019-01-11):
# Per an announcement on the Metlakatla community's official Facebook page, the
# "fall back" will be on Sunday 2019-01-20 at 02:00:
# https://www.facebook.com/141055983004923/photos/607150969728753/
# So they won't be waiting for Alaska to join them on 2019-03-10, but will
# rather change their clocks twice in seven weeks.

# From Paul Eggert (2023-01-23):
# America/Adak is for the Aleutian Islands that are part of Alaska
# and are west of 169.5° W.

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 19 15:33:32
			 -8:57:41 -	LMT	1900 Aug 20 12:00
			 -8:00	-	PST	1942
			 -8:00	US	P%sT	1946
			 -8:00	-	PST	1969
			 -8:00	US	P%sT	1980 Apr 27  2:00
			 -9:00	US	Y%sT	1980 Oct 26  2:00
			 -8:00	US	P%sT	1983 Oct 30  2:00
			 -9:00	US	Y%sT	1983 Nov 30
			 -9:00	US	AK%sT
Zone America/Sitka	 14:58:47 -	LMT	1867 Oct 19 15:30
			 -9:01:13 -	LMT	1900 Aug 20 12:00
			 -8:00	-	PST	1942
			 -8:00	US	P%sT	1946
			 -8:00	-	PST	1969
			 -8:00	US	P%sT	1983 Oct 30  2:00
			 -9:00	US	Y%sT	1983 Nov 30
			 -9:00	US	AK%sT
Zone America/Metlakatla	 15:13:42 -	LMT	1867 Oct 19 15:44:55
			 -8:46:18 -	LMT	1900 Aug 20 12:00
			 -8:00	-	PST	1942
			 -8:00	US	P%sT	1946
			 -8:00	-	PST	1969
			 -8:00	US	P%sT	1983 Oct 30  2:00
			 -8:00	-	PST	2015 Nov  1  2:00
			 -9:00	US	AK%sT	2018 Nov  4  2:00
			 -8:00	-	PST	2019 Jan 20  2:00
			 -9:00	US	AK%sT
Zone America/Yakutat	 14:41:05 -	LMT	1867 Oct 19 15:12:18
			 -9:18:55 -	LMT	1900 Aug 20 12:00
			 -9:00	-	YST	1942
			 -9:00	US	Y%sT	1946
			 -9:00	-	YST	1969
			 -9:00	US	Y%sT	1983 Nov 30
			 -9:00	US	AK%sT
Zone America/Anchorage	 14:00:24 -	LMT	1867 Oct 19 14:31:37
			 -9:59:36 -	LMT	1900 Aug 20 12:00
			-10:00	-	AST	1942
			-10:00	US	A%sT	1967 Apr
			-10:00	-	AHST	1969
			-10:00	US	AH%sT	1983 Oct 30  2:00
			 -9:00	US	Y%sT	1983 Nov 30
			 -9:00	US	AK%sT
Zone America/Nome	 12:58:22 -	LMT	1867 Oct 19 13:29:35
			-11:01:38 -	LMT	1900 Aug 20 12:00
			-11:00	-	NST	1942
			-11:00	US	N%sT	1946
			-11:00	-	NST	1967 Apr
			-11:00	-	BST	1969
			-11:00	US	B%sT	1983 Oct 30  2:00
			 -9:00	US	Y%sT	1983 Nov 30
			 -9:00	US	AK%sT
Zone America/Adak	 12:13:22 -	LMT	1867 Oct 19 12:44:35
			-11:46:38 -	LMT	1900 Aug 20 12:00
			-11:00	-	NST	1942
			-11:00	US	N%sT	1946
			-11:00	-	NST	1967 Apr
			-11:00	-	BST	1969
			-11:00	US	B%sT	1983 Oct 30  2:00
			-10:00	US	AH%sT	1983 Nov 30
			-10:00	US	H%sT
# The following switches don't make our 1970 cutoff.
#
# Kiska observed Tokyo date and time during Japanese occupation from
# 1942-06-06 to 1943-07-29, and similarly for Attu from 1942-06-07 to
# 1943-05-29 (all dates American).  Both islands are now uninhabited.
#
# Shanks writes that part of southwest Alaska (e.g. Aniak)
# switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
# and another part (e.g. Akiak) made the same switch five weeks later.
#
# From David Flater (2004-11-09):
# In e-mail, 2004-11-02, Ray Hudson, historian/liaison to the Unalaska
# Historic Preservation Commission, provided this information, which
# suggests that Unalaska deviated from statutory time from early 1967
# possibly until 1983:
#
#  Minutes of the Unalaska City Council Meeting, January 10, 1967:
#  "Except for St. Paul and Akutan, Unalaska is the only important
#  location not on Alaska Standard Time.  The following resolution was
#  made by William Robinson and seconded by Henry Swanson: Be it
#  resolved that the City of Unalaska hereby goes to Alaska Standard
#  Time as of midnight Friday, January 13, 1967 (1 A.M. Saturday,
#  January 14, Alaska Standard Time.)  This resolution was passed with
#  three votes for and one against."

# Hawaii

# From Arthur David Olson (2010-12-09):
# "Hawaiian Time" by Robert C. Schmitt and Doak C. Cox appears on pages 207-225
# of volume 26 of The Hawaiian Journal of History (1992). As of 2010-12-09,
# the article is available at
# https://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
# and indicates that standard time was adopted effective noon, January
# 13, 1896 (page 218), that in "1933, the Legislature decreed daylight
# saving for the period between the last Sunday of each April and the
# last Sunday of each September, but less than a month later repealed the
# act," (page 220), that year-round daylight saving time was in effect
# from 1942-02-09 to 1945-09-30 (page 221, with no time of day given for
# when clocks changed) and that clocks were changed by 30 minutes
# effective the second Sunday of June, 1947 (page 219, with no time of
# day given for when clocks changed). A footnote for the 1933 changes
# cites Session Laws of Hawaii 1933, "Act. 90 (approved 26 Apr. 1933)
# and Act 163 (approved 21 May 1933)."

# From Arthur David Olson (2011-01-19):
# The following is from "Laws of the Territory of Hawaii Passed by the
# Seventeenth Legislature: Regular Session 1933," available (as of
# 2011-01-19) at American University's Pence Law Library. Page 85: "Act
# 90...At 2 o'clock ante meridian of the last Sunday in April of each
# year, the standard time of this Territory shall be advanced one
# hour...This Act shall take effect upon its approval. Approved this 26th
# day of April, A. D. 1933. LAWRENCE M JUDD, Governor of the Territory of
# Hawaii." Page 172: "Act 163...Act 90 of the Session Laws of 1933 is
# hereby repealed...This Act shall take effect upon its approval, upon
# which date the standard time of this Territory shall be restored to
# that existing immediately prior to the taking effect of said Act 90.
# Approved this 21st day of May, A. D. 1933. LAWRENCE M. JUDD, Governor
# of the Territory of Hawaii."
#
# Note that 1933-05-21 was a Sunday.
# We're left to guess the time of day when Act 163 was approved; guess noon.

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone Pacific/Honolulu	-10:31:26 -	LMT	1896 Jan 13 12:00
			-10:30	-	HST	1933 Apr 30  2:00
			-10:30	1:00	HDT	1933 May 21 12:00
			-10:30	US	H%sT	1947 Jun  8  2:00
			-10:00	-	HST

# Now we turn to US areas that have diverged from the consensus since 1970.

# Arizona mostly uses MST.

# From Paul Eggert (2002-10-20):
#
# The information in the rest of this paragraph is derived from the
# Daylight Saving Time web page
# <http://www.dlapr.lib.az.us/links/daylight.htm> (2002-01-23)
# maintained by the Arizona State Library, Archives and Public Records.
# Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
# time, but by federal law railroads, airlines, bus lines, military
# personnel, and some engaged in interstate commerce continued to
# observe war (i.e., daylight saving) time.  The 1944-03-17 Phoenix
# Gazette says that was the date the law changed, and that 04-01 was
# the date the state's clocks would change.  In 1945 the State of
# Arizona used standard time all year, again with exceptions only as
# mandated by federal law.  Arizona observed DST in 1967, but Arizona
# Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
#
# Shanks says the 1944 experiment came to an end on 1944-03-17.
# Go with the Arizona State Library instead.

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Phoenix	-7:28:18 -	LMT	1883 Nov 18 19:00u
			-7:00	US	M%sT	1944 Jan  1  0:01
			-7:00	-	MST	1944 Apr  1  0:01
			-7:00	US	M%sT	1944 Oct  1  0:01
			-7:00	-	MST	1967
			-7:00	US	M%sT	1968 Mar 21
			-7:00	-	MST

# From Arthur David Olson (1988-02-13):
# A writer from the Inter Tribal Council of Arizona, Inc.,
# notes in private correspondence dated 1987-12-28 that "Presently, only the
# Navajo Nation participates in the Daylight Saving Time policy, due to its
# large size and location in three states."  (The "only" means that other
# tribal nations don't use DST.)
#
# From Paul Eggert (2013-08-26):
# See America/Denver for a zone appropriate for the Navajo Nation.

# Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
# Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
# Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
# Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
# Teton, Twin Falls, Valley, Washington counties, and the southern
# quarter of Idaho county) and eastern Oregon (most of Malheur County)
# switched four weeks late in 1974.
#
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Boise	-7:44:49 -	LMT	1883 Nov 18 20:00u
			-8:00	US	P%sT	1923 May 13  2:00
			-7:00	US	M%sT	1974
			-7:00	-	MST	1974 Feb  3  2:00
			-7:00	US	M%sT

# Indiana
#
# For a map of Indiana's time zone regions, see:
# https://en.wikipedia.org/wiki/Time_in_Indiana
#
# From Paul Eggert (2018-11-30):
# A brief but entertaining history of time in Indiana describes a 1949 debate
# in the Indiana House where city legislators (who favored "fast time")
# tussled with farm legislators (who didn't) over a bill to outlaw DST:
#  "Lacking enough votes, the city faction tries to filibuster until time runs
#   out on the session at midnight, but rural champion Rep. Herbert Copeland,
#   R-Madison, leans over the gallery railing and forces the official clock
#   back to 9 p.m., breaking it in the process.  The clock sticks on 9 as the
#   debate rages on into the night.  The filibuster finally dies out and the
#   bill passes, while outside the chamber, clocks read 3:30 a.m.  In the end,
#   it doesn't matter which side won.  The law has no enforcement powers and
#   is simply ignored by fast-time communities."
# How Indiana went from 'God's time' to split zones and daylight-saving.
# Indianapolis Star. 2018-11-27 14:58 -05.
# https://www.indystar.com/story/news/politics/2018/11/27/indianapolis-indiana-time-zone-history-central-eastern-daylight-savings-time/2126300002/
#
# From Paul Eggert (2007-08-17):
# Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
# with the following exceptions:
#
# - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
#   Vanderburgh, and Warrick counties have been like America/Chicago.
#
# - Dearborn and Ohio counties have been like America/New_York.
#
# - Clark, Floyd, and Harrison counties have been like
#   America/Kentucky/Louisville.
#
# - Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
#   and Switzerland counties have their own time zone histories as noted below.
#
# Shanks partitioned Indiana into 345 regions, each with its own time history,
# and wrote "Even newspaper reports present contradictory information."
# Those Hoosiers!  Such a flighty and changeable people!
# Fortunately, most of the complexity occurred before our cutoff date of 1970.
#
# Other than Indianapolis, the Indiana place names are so nondescript
# that they would be ambiguous if we left them at the 'America' level.
# So we reluctantly put them all in a subdirectory 'America/Indiana'.

# From Paul Eggert (2014-06-26):
# https://www.federalregister.gov/articles/2006/01/20/06-563/standard-time-zone-boundary-in-the-state-of-indiana
# says "DOT is relocating the time zone boundary in Indiana to move Starke,
# Pulaski, Knox, Daviess, Martin, Pike, Dubois, and Perry Counties from the
# Eastern Time Zone to the Central Time Zone.... The effective date of
# this rule is 2 a.m. EST Sunday, April 2, 2006, which is the
# changeover date from standard time to Daylight Saving Time."
# Strictly speaking, this meant the affected counties changed their
# clocks twice that night, but this obviously was in error.  The intent
# was that 01:59:59 EST be followed by 02:00:00 CDT.

# From Gwillim Law (2007-02-10):
# The Associated Press has been reporting that Pulaski County, Indiana is
# going to switch from Central to Eastern Time on March 11, 2007....
# http://www.indystar.com/apps/pbcs.dll/article?AID=/20070207/LOCAL190108/702070524/0/LOCAL

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule Indianapolis 1941	only	-	Jun	22	2:00	1:00	D
Rule Indianapolis 1941	1954	-	Sep	lastSun	2:00	0	S
Rule Indianapolis 1946	1954	-	Apr	lastSun	2:00	1:00	D
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Indianapolis -5:44:38 - LMT 1883 Nov 18 18:00u
			-6:00	US	C%sT	1920
			-6:00 Indianapolis C%sT	1942
			-6:00	US	C%sT	1946
			-6:00 Indianapolis C%sT	1955 Apr 24  2:00
			-5:00	-	EST	1957 Sep 29  2:00
			-6:00	-	CST	1958 Apr 27  2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1971
			-5:00	-	EST	2006
			-5:00	US	E%sT
#
# Eastern Crawford County, Indiana, left its clocks alone in 1974,
# as well as from 1976 through 2005.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Marengo	1951	only	-	Apr	lastSun	2:00	1:00	D
Rule	Marengo	1951	only	-	Sep	lastSun	2:00	0	S
Rule	Marengo	1954	1960	-	Apr	lastSun	2:00	1:00	D
Rule	Marengo	1954	1960	-	Sep	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Marengo -5:45:23 -	LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1951
			-6:00	Marengo	C%sT	1961 Apr 30  2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1974 Jan  6  2:00
			-6:00	1:00	CDT	1974 Oct 27  2:00
			-5:00	US	E%sT	1976
			-5:00	-	EST	2006
			-5:00	US	E%sT
#
# Daviess, Dubois, Knox, and Martin Counties, Indiana,
# switched from eastern to central time in April 2006, then switched back
# in November 2007.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule Vincennes	1946	only	-	Apr	lastSun	2:00	1:00	D
Rule Vincennes	1946	only	-	Sep	lastSun	2:00	0	S
Rule Vincennes	1953	1954	-	Apr	lastSun	2:00	1:00	D
Rule Vincennes	1953	1959	-	Sep	lastSun	2:00	0	S
Rule Vincennes	1955	only	-	May	 1	0:00	1:00	D
Rule Vincennes	1956	1963	-	Apr	lastSun	2:00	1:00	D
Rule Vincennes	1960	only	-	Oct	lastSun	2:00	0	S
Rule Vincennes	1961	only	-	Sep	lastSun	2:00	0	S
Rule Vincennes	1962	1963	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Vincennes -5:50:07 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1946
			-6:00 Vincennes	C%sT	1964 Apr 26  2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1971
			-5:00	-	EST	2006 Apr  2  2:00
			-6:00	US	C%sT	2007 Nov  4  2:00
			-5:00	US	E%sT
#
# Perry County, Indiana, switched from eastern to central time in April 2006.
# From Alois Treindl (2019-07-09):
# The Indianapolis News, Friday 27 October 1967 states that Perry County
# returned to CST.  It went again to EST on 27 April 1969, as documented by the
# Indianapolis star of Saturday 26 April.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule Perry	1955	only	-	May	 1	0:00	1:00	D
Rule Perry	1955	1960	-	Sep	lastSun	2:00	0	S
Rule Perry	1956	1963	-	Apr	lastSun	2:00	1:00	D
Rule Perry	1961	1963	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Tell_City -5:47:03 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1946
			-6:00 Perry	C%sT	1964 Apr 26  2:00
			-5:00	-	EST	1967 Oct 29  2:00
			-6:00	US	C%sT	1969 Apr 27  2:00
			-5:00	US	E%sT	1971
			-5:00	-	EST	2006 Apr  2  2:00
			-6:00	US	C%sT
#
# Pike County, Indiana moved from central to eastern time in 1977,
# then switched back in 2006, then switched back again in 2007.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Pike	1955	only	-	May	 1	0:00	1:00	D
Rule	Pike	1955	1960	-	Sep	lastSun	2:00	0	S
Rule	Pike	1956	1964	-	Apr	lastSun	2:00	1:00	D
Rule	Pike	1961	1964	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Petersburg -5:49:07 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1955
			-6:00	Pike	C%sT	1965 Apr 25  2:00
			-5:00	-	EST	1966 Oct 30  2:00
			-6:00	US	C%sT	1977 Oct 30  2:00
			-5:00	-	EST	2006 Apr  2  2:00
			-6:00	US	C%sT	2007 Nov  4  2:00
			-5:00	US	E%sT
#
# Starke County, Indiana moved from central to eastern time in 1991,
# then switched back in 2006.
# From Arthur David Olson (1991-10-28):
# An article on page A3 of the Sunday, 1991-10-27 Washington Post
# notes that Starke County switched from Central time to Eastern time as of
# 1991-10-27.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Starke	1947	1961	-	Apr	lastSun	2:00	1:00	D
Rule	Starke	1947	1954	-	Sep	lastSun	2:00	0	S
Rule	Starke	1955	1956	-	Oct	lastSun	2:00	0	S
Rule	Starke	1957	1958	-	Sep	lastSun	2:00	0	S
Rule	Starke	1959	1961	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Knox -5:46:30 -	LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1947
			-6:00	Starke	C%sT	1962 Apr 29  2:00
			-5:00	-	EST	1963 Oct 27  2:00
			-6:00	US	C%sT	1991 Oct 27  2:00
			-5:00	-	EST	2006 Apr  2  2:00
			-6:00	US	C%sT
#
# Pulaski County, Indiana, switched from eastern to central time in
# April 2006 and then switched back in March 2007.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Pulaski	1946	1960	-	Apr	lastSun	2:00	1:00	D
Rule	Pulaski	1946	1954	-	Sep	lastSun	2:00	0	S
Rule	Pulaski	1955	1956	-	Oct	lastSun	2:00	0	S
Rule	Pulaski	1957	1960	-	Sep	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Winamac -5:46:25 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1946
			-6:00	Pulaski	C%sT	1961 Apr 30  2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1971
			-5:00	-	EST	2006 Apr  2  2:00
			-6:00	US	C%sT	2007 Mar 11  2:00
			-5:00	US	E%sT
#
# Switzerland County, Indiana, did not observe DST from 1973 through 2005.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Vevay -5:40:16 -	LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1954 Apr 25  2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1973
			-5:00	-	EST	2006
			-5:00	US	E%sT

# From Paul Eggert (2018-03-20):
# The Louisville & Nashville Railroad's 1883-11-18 change occurred at
# 10:00 old local time; train were supposed to come to a standstill
# for precisely 18 minutes.  See Bartky Fig. 1 (page 50).  It is not
# clear how this matched civil time in Louisville, so for now continue
# to assume Louisville switched at noon new local time, like New York.
#
# From Michael Deckers (2019-08-06):
# From the contemporary source given by Alois Treindl,
# the switch in Louisville on 1946-04-28 was on 00:01
# From Paul Eggert (2019-08-26):
# That source was the Louisville Courier-Journal, 1946-04-27, p 4.
# Shanks gives 02:00 for all 20th-century transition times in Louisville.
# Evidently this is wrong for spring 1946.  Although also likely wrong
# for other dates, we have no data.
#
# Part of Kentucky left its clocks alone in 1974.
# This also includes Clark, Floyd, and Harrison counties in Indiana.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule Louisville	1921	only	-	May	1	2:00	1:00	D
Rule Louisville	1921	only	-	Sep	1	2:00	0	S
Rule Louisville	1941	only	-	Apr	lastSun	2:00	1:00	D
Rule Louisville	1941	only	-	Sep	lastSun	2:00	0	S
Rule Louisville	1946	only	-	Apr	lastSun	0:01	1:00	D
Rule Louisville	1946	only	-	Jun	2	2:00	0	S
Rule Louisville	1950	1961	-	Apr	lastSun	2:00	1:00	D
Rule Louisville	1950	1955	-	Sep	lastSun	2:00	0	S
Rule Louisville	1956	1961	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Kentucky/Louisville -5:43:02 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1921
			-6:00 Louisville C%sT	1942
			-6:00	US	C%sT	1946
			-6:00 Louisville C%sT	1961 Jul 23  2:00
			-5:00	-	EST	1968
			-5:00	US	E%sT	1974 Jan  6  2:00
			-6:00	1:00	CDT	1974 Oct 27  2:00
			-5:00	US	E%sT
#
# Wayne County, Kentucky
#
# From Lake Cumberland LIFE
# http://www.lake-cumberland.com/life/archive/news990129time.shtml
# (1999-01-29) via WKYM-101.7:
# Clinton County has joined Wayne County in asking the DoT to change from
# the Central to the Eastern time zone....  The Wayne County government made
# the same request in December.  And while Russell County officials have not
# taken action, the majority of respondents to a poll conducted there in
# August indicated they would like to change to "fast time" also.
# The three Lake Cumberland counties are the farthest east of any U.S.
# location in the Central time zone.
#
# From Rich Wales (2000-08-29):
# After prolonged debate, and despite continuing deep differences of opinion,
# Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
# (-0500) time.  They won't "fall back" this year.  See Sara Shipley,
# The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
#
# From Paul Eggert (2001-07-16):
# The final rule was published in the
# Federal Register 65, 160 (2000-08-17), pp 50154-50158.
# https://www.gpo.gov/fdsys/pkg/FR-2000-08-17/html/00-20854.htm
#
Zone America/Kentucky/Monticello -5:39:24 - LMT	1883 Nov 18 18:00u
			-6:00	US	C%sT	1946
			-6:00	-	CST	1968
			-6:00	US	C%sT	2000 Oct 29  2:00
			-5:00	US	E%sT


# From Rives McDow (2000-08-30):
# Here ... are all the changes in the US since 1985.
# Kearny County, KS (put all of county on central;
#	previously split between MST and CST) ... 1990-10
# Starke County, IN (from CST to EST) ... 1991-10
# Oliver County, ND (from MST to CST) ... 1992-10
# West Wendover, NV (from PST TO MST) ... 1999-10
# Wayne County, KY (from CST to EST) ... 2000-10
#
# From Paul Eggert (2001-07-17):
# We don't know where the line used to be within Kearny County, KS,
# so omit that change for now.
# See America/Indiana/Knox for the Starke County, IN change.
# See America/North_Dakota/Center for the Oliver County, ND change.
# West Wendover, NV officially switched from Pacific to mountain time on
# 1999-10-31.  See the
# Federal Register 64, 203 (1999-10-21), pp 56705-56707.
# https://www.gpo.gov/fdsys/pkg/FR-1999-10-21/html/99-27240.htm
# However, the Federal Register says that West Wendover already operated
# on mountain time, and the rule merely made this official;
# hence a separate tz entry is not needed.

# Michigan
#
# From Bob Devine (1988-01-28):
# Michigan didn't observe DST from 1968 to 1973.
#
# From Paul Eggert (1999-03-31):
# Shanks writes that Michigan started using standard time on 1885-09-18,
# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
# that Detroit kept
#
#	local time until 1900 when the City Council decreed that clocks should
#	be put back twenty-eight minutes to Central Standard Time.  Half the
#	city obeyed, half refused.  After considerable debate, the decision
#	was rescinded and the city reverted to Sun time.  A derisive offer to
#	erect a sundial in front of the city hall was referred to the
#	Committee on Sewers.  Then, in 1905, Central time was adopted
#	by city vote.
#
# This story is too entertaining to be false, so go with Howse over Shanks.
#
# From Paul Eggert (2001-03-06):
# Garland (1927) writes "Cleveland and Detroit advanced their clocks
# one hour in 1914."  This change is not in Shanks.  We have no more
# info, so omit this for now.
#
# From Paul Eggert (2019-07-06):
# Due to a complicated set of legal maneuvers, in 1967 Michigan did
# not start daylight saving time when the rest of the US did.
# Instead, it began DST on Jun 14 at 00:01.  This was big news:
# the Detroit Free Press reported it at the top of Page 1 on
# 1967-06-14, in an article "State Adjusting to Switch to Fast Time"
# by Gary Blonston, above an article about Thurgood Marshall's
# confirmation to the US Supreme Court.  Although Shanks says Detroit
# observed DST until 1967-10-29 00:01, that time of day seems to be
# incorrect, as the Free Press later said DST ended in Michigan at the
# same time as the rest of the US.  Also, although Shanks reports no DST in
# Detroit in 1968, it did observe DST that year; in the November 1968
# election Michigan voters narrowly repealed DST, effective 1969.
#
# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule	Detroit	1948	only	-	Apr	lastSun	2:00	1:00	D
Rule	Detroit	1948	only	-	Sep	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Detroit	-5:32:11 -	LMT	1905
			-6:00	-	CST	1915 May 15  2:00
			-5:00	-	EST	1942
			-5:00	US	E%sT	1946
			-5:00	Detroit	E%sT	1967 Jun 14  0:01
			-5:00	US	E%sT	1969
			-5:00	-	EST	1973
			-5:00	US	E%sT	1975
			-5:00	-	EST	1975 Apr 27  2:00
			-5:00	US	E%sT
#
# Dickinson, Gogebic, Iron, and Menominee Counties, Michigan,
# switched from EST to CST/CDT in 1973.
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER
Rule Menominee	1946	only	-	Apr	lastSun	2:00	1:00	D
Rule Menominee	1946	only	-	Sep	lastSun	2:00	0	S
Rule Menominee	1966	only	-	Apr	lastSun	2:00	1:00	D
Rule Menominee	1966	only	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Menominee	-5:50:27 -	LMT	1885 Sep 18 12:00
			-6:00	US	C%sT	1946
			-6:00 Menominee	C%sT	1969 Apr 27  2:00
			-5:00	-	EST	1973 Apr 29  2:00
			-6:00	US	C%sT

# Navassa
# administered by the US Fish and Wildlife Service
# claimed by US under the provisions of the 1856 Guano Islands Act
# also claimed by Haiti
# occupied 1857/1900 by the Navassa Phosphate Co
# US lighthouse 1917/1996-09
# currently uninhabited
# see Mark Fineman, "An Isle Rich in Guano and Discord",
# _Los Angeles Times_ (1998-11-10), A1, A10; it cites
# Jimmy Skaggs, _The Great Guano Rush_ (1994).

# From Rob van Gent (2025-07-23):
# Another useful source for historical time zone information appears to be
# a series of circulars with the title "Standard Time Throughout the World"
# issued between 1925 and 1950 by the U.S. Bureau of Standards.
# I found the following issues online:
# https://nvlpubs.nist.gov/nistpubs/Legacy/circ/nbscircular280.pdf (1925)
# https://nvlpubs.nist.gov/nistpubs/Legacy/circ/nbscircular399.pdf (1932)
# https://nvlpubs.nist.gov/nistpubs/Legacy/circ/nbscircular406.pdf (1935)
# https://nvlpubs.nist.gov/nistpubs/Legacy/circ/nbscircular496.pdf (1950)

################################################################################


# From Paul Eggert (2017-02-10):
#
# 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.
#
# Other sources occasionally used include:
#
#	Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
#	<https://www.jstor.org/stable/1774359>.
#
#	Pearce C. The Great Daylight Saving Time Controversy.
#	Australian Ebook Publisher. 2017. ISBN 978-1-925516-96-8.
#
#	Edward W. Whitman, World Time Differences,
#	Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
#	which I found in the UCLA library.
#
#	William Willett, The Waste of Daylight, 19th edition
#	<http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
#	[PDF] (1914-03)
#
# For the 1911/1912 establishment of standard time in French possessions, see:
# Société Française de Physique, Recueil de constantes physiques (1913),
# page 752, 18b.
#
# See the 'europe' file for Greenland.

# Canada

# From Alain LaBonté (1994-11-14):
# I post here the time zone abbreviations standardized in Canada
# for both English and French in the CAN/CSA-Z234.4-89 standard....
#
#	UTC	Standard time	Daylight saving time
#	offset	French	English	French	English
#	-2:30	-	-	HAT	NDT
#	-3	-	-	HAA	ADT
#	-3:30	HNT	NST	-	-
#	-4	HNA	AST	HAE	EDT
#	-5	HNE	EST	HAC	CDT
#	-6	HNC	CST	HAR	MDT
#	-7	HNR	MST	HAP	PDT
#	-8	HNP	PST	HAY	YDT
#	-9	HNY	YST	-	-
#
#	HN: Heure Normale	ST: Standard Time
#	HA: Heure Avancée	DT: Daylight saving Time
#
#	A: de l'Atlantique	Atlantic
#	C: du Centre		Central
#	E: de l'Est		Eastern
#	M:			Mountain
#	N:			Newfoundland
#	P: du Pacifique		Pacific
#	R: des Rocheuses
#	T: de Terre-Neuve
#	Y: du Yukon		Yukon
#
# From Paul Eggert (1994-11-22):
# Alas, this sort of thing must be handled by localization software.

# Unless otherwise specified, the data entries for Canada are all from Shanks
# & Pottenger.

# From Chris Walton (2006-04-01, 2006-04-25, 2006-06-26, 2007-01-31,
# 2007-03-01):
# The British Columbia government announced yesterday that it will
# adjust daylight savings next year to align with changes in the
# U.S. and the rest of Canada....
# https://archive.news.gov.bc.ca/releases/news_releases_2005-2009/2006AG0014-000330.htm
# ...
# Nova Scotia
# Daylight saving time will be extended by four weeks starting in 2007....
# https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
#
# [For New Brunswick] the new legislation dictates that the time change is to
# be done at 02:00 instead of 00:01.
# https://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
# ...
# Manitoba has traditionally changed the clock every fall at 03:00.
# As of 2006, the transition is to take place one hour earlier at 02:00.
# https://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
# ...
# [Alberta, Ontario, Quebec] will follow US rules.
# http://www.qp.gov.ab.ca/documents/spring/CH03_06.CFM
# http://www.e-laws.gov.on.ca/DBLaws/Source/Regs/English/2006/R06111_e.htm
# http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=5&file=2006C39A.PDF
# ...
# P.E.I. will follow US rules....
# http://www.assembly.pe.ca/bills/pdf_chapter/62/3/chapter-41.pdf
# ...
# Province of Newfoundland and Labrador....
# http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
# ...
# Yukon
# https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
# ...
# N.W.T. will follow US rules.  Whoever maintains the government web site
# does not seem to believe in bookmarks.  To see the news release, click the
# following link and search for "Daylight Savings Time Change".  Press the
# "Daylight Savings Time Change" link; it will fire off a popup using
# JavaScript.
# http://www.exec.gov.nt.ca/currentnews/currentPR.asp?mode=archive
# ...
# Nunavut
# An amendment to the Interpretation Act was registered on February 19/2007....
# http://action.attavik.ca/home/justice-gn/attach/2007/gaz02part2.pdf

# From Paul Eggert (2014-10-18):
# H. David Matthews and Mary Vincent's map
# "It's about TIME", _Canadian Geographic_ (September-October 1998)
# https://web.archive.org/web/19990827055050/https://canadiangeographic.ca/SO98/geomap.htm
# contains detailed boundaries for regions observing nonstandard
# time and daylight saving time arrangements in Canada circa 1998.
#
# National Research Council Canada maintains info about time zones and DST.
# https://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
# https://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
# Its unofficial information is often taken from Matthews and Vincent.

# From Paul Eggert (2006-06-27):
# For now, assume all of DST-observing Canada will fall into line with the
# new US DST rules,

# From Chris Walton (2011-12-01)
# In the first of Tammy Hardwick's articles
# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
# she quotes the Friday November 1/1918 edition of the Creston Review.
# The quote includes these two statements:
# 'Sunday the CPR went back to the old system of time...'
# '... The daylight saving scheme was dropped all over Canada at the same time,'
# These statements refer to a transition from daylight time to standard time
# that occurred nationally on Sunday October 27/1918.  This transition was
# also documented in the Saturday October 26/1918 edition of the Toronto Star.

# In light of that evidence, we alter the date from the earlier believed
# Oct 31, to Oct 27, 1918 (and Sunday is a more likely transition day
# than Thursday) in all Canadian rulesets.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Canada	1918	only	-	Apr	14	2:00	1:00	D
Rule	Canada	1918	only	-	Oct	27	2:00	0	S
Rule	Canada	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	Canada	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	Canada	1945	only	-	Sep	30	2:00	0	S
Rule	Canada	1974	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Canada	1974	2006	-	Oct	lastSun	2:00	0	S
Rule	Canada	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
Rule	Canada	2007	max	-	Mar	Sun>=8	2:00	1:00	D
Rule	Canada	2007	max	-	Nov	Sun>=1	2:00	0	S


# Newfoundland and Labrador

# From Paul Eggert (2017-10-14):
# Legally Labrador should observe Newfoundland time; see:
# McLeod J. Labrador time - legal or not? St. John's Telegram, 2017-10-07
# http://www.thetelegram.com/news/local/labrador-time--legal-or-not-154860/
# Matthews and Vincent (1998) write that the only part of Labrador
# that follows the rules is the southeast corner, including Port Hope
# Simpson and Mary's Harbour, but excluding, say, Black Tickle.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	StJohns	1917	only	-	Apr	 8	2:00	1:00	D
Rule	StJohns	1917	only	-	Sep	17	2:00	0	S
# Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
Rule	StJohns	1919	only	-	May	 5	23:00	1:00	D
Rule	StJohns	1919	only	-	Aug	12	23:00	0	S
# For 1931-1935 Whitman gives Apr same date; go with Shanks & Pottenger.
Rule	StJohns	1920	1935	-	May	Sun>=1	23:00	1:00	D
Rule	StJohns	1920	1935	-	Oct	lastSun	23:00	0	S
# For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks &
# Pottenger.
Rule	StJohns	1936	1941	-	May	Mon>=9	0:00	1:00	D
Rule	StJohns	1936	1941	-	Oct	Mon>=2	0:00	0	S
# Whitman gives the following transitions:
# 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
# but go with Shanks & Pottenger and assume they used Canadian rules.
# For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
# Apr 30 - Sep 24; go with Shanks & Pottenger.
Rule	StJohns	1946	1950	-	May	Sun>=8	2:00	1:00	D
Rule	StJohns	1946	1950	-	Oct	Sun>=2	2:00	0	S
Rule	StJohns	1951	1986	-	Apr	lastSun	2:00	1:00	D
Rule	StJohns	1951	1959	-	Sep	lastSun	2:00	0	S
Rule	StJohns	1960	1986	-	Oct	lastSun	2:00	0	S
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
# at 00:01 local time.  For now, assume it started in 1987.

# From Michael Pelley (2011-09-12):
# We received today, Monday, September 12, 2011, notification that the
# changes to the Newfoundland Standard Time Act have been proclaimed.
# The change in the Act stipulates that the change from Daylight Savings
# Time to Standard Time and from Standard Time to Daylight Savings Time
# now occurs at 2:00AM.
# ...
# http://www.assembly.nl.ca/legislation/sr/annualstatutes/2011/1106.chp.htm
# ...
# MICHAEL PELLEY  |  Manager of Enterprise Architecture - Solution Delivery
# Office of the Chief Information Officer
# Executive Council
# Government of Newfoundland & Labrador

Rule	StJohns	1987	only	-	Apr	Sun>=1	0:01	1:00	D
Rule	StJohns	1987	2006	-	Oct	lastSun	0:01	0	S
Rule	StJohns	1988	only	-	Apr	Sun>=1	0:01	2:00	DD
Rule	StJohns	1989	2006	-	Apr	Sun>=1	0:01	1:00	D
Rule	StJohns	2007	2011	-	Mar	Sun>=8	0:01	1:00	D
Rule	StJohns	2007	2010	-	Nov	Sun>=1	0:01	0	S
#
# St John's has an apostrophe, but POSIX file names can't have apostrophes.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Johns	-3:30:52 -	LMT	1884
			-3:30:52 StJohns N%sT	1918
			-3:30:52 Canada	N%sT	1919
			-3:30:52 StJohns N%sT	1935 Mar 30
			-3:30	StJohns	N%sT	1942 May 11
			-3:30	Canada	N%sT	1946
			-3:30	StJohns	N%sT	2011 Nov
			-3:30	Canada	N%sT

# most of east Labrador

# The name 'Happy Valley-Goose Bay' is too long; use 'Goose Bay'.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Goose_Bay	-4:01:40 -	LMT	1884 # Happy Valley-Goose Bay
			-3:30:52 -	NST	1918
			-3:30:52 Canada N%sT	1919
			-3:30:52 -	NST	1935 Mar 30
			-3:30	-	NST	1936
			-3:30	StJohns	N%sT	1942 May 11
			-3:30	Canada	N%sT	1946
			-3:30	StJohns	N%sT	1966 Mar 15  2:00
			-4:00	StJohns	A%sT	2011 Nov
			-4:00	Canada	A%sT


# west Labrador, Nova Scotia, Prince Edward I,
# Îles-de-la-Madeleine, Listuguj reserve

# From Brian Inglis (2015-07-20):
# From the historical weather station records available at:
# https://weatherspark.com/history/28351/1971/Sydney-Nova-Scotia-Canada
# Sydney shares the same time history as Glace Bay, so was
# likely to be the same across the island....
# Sydney, as the capital and most populous location, or Cape Breton, would
# have been better names for the zone had we known this in 1996.

# From Paul Eggert (2015-07-20):
# Shanks & Pottenger write that since 1970 most of this region has been like
# Halifax.  Many locales did not observe peacetime DST until 1972;
# the Cape Breton area, represented by Glace Bay, is the largest we know of
# (Glace Bay was perhaps not the best name choice but no point changing now).
# Shanks & Pottenger also write that Liverpool, NS was the only town
# in Canada to observe DST in 1971 but not 1970; for now we'll assume
# this is a typo.

# From Jeffery Nichols (2020-01-09):
# America/Halifax ... also applies to Îles-de-la-Madeleine and the Listuguj
# reserve in Quebec. Officially, this came into effect on January 1, 2007
# (Legal Time Act, CQLR c T-5.1), but the legislative debates surrounding that
# bill say that it is "accommodating the customs and practices" of those
# regions, which suggests that they have always been in-line with Halifax.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Halifax	1916	only	-	Apr	 1	0:00	1:00	D
Rule	Halifax	1916	only	-	Oct	 1	0:00	0	S
Rule	Halifax	1920	only	-	May	 9	0:00	1:00	D
Rule	Halifax	1920	only	-	Aug	29	0:00	0	S
Rule	Halifax	1921	only	-	May	 6	0:00	1:00	D
Rule	Halifax	1921	1922	-	Sep	 5	0:00	0	S
Rule	Halifax	1922	only	-	Apr	30	0:00	1:00	D
Rule	Halifax	1923	1925	-	May	Sun>=1	0:00	1:00	D
Rule	Halifax	1923	only	-	Sep	 4	0:00	0	S
Rule	Halifax	1924	only	-	Sep	15	0:00	0	S
Rule	Halifax	1925	only	-	Sep	28	0:00	0	S
Rule	Halifax	1926	only	-	May	16	0:00	1:00	D
Rule	Halifax	1926	only	-	Sep	13	0:00	0	S
Rule	Halifax	1927	only	-	May	 1	0:00	1:00	D
Rule	Halifax	1927	only	-	Sep	26	0:00	0	S
Rule	Halifax	1928	1931	-	May	Sun>=8	0:00	1:00	D
Rule	Halifax	1928	only	-	Sep	 9	0:00	0	S
Rule	Halifax	1929	only	-	Sep	 3	0:00	0	S
Rule	Halifax	1930	only	-	Sep	15	0:00	0	S
Rule	Halifax	1931	1932	-	Sep	Mon>=24	0:00	0	S
Rule	Halifax	1932	only	-	May	 1	0:00	1:00	D
Rule	Halifax	1933	only	-	Apr	30	0:00	1:00	D
Rule	Halifax	1933	only	-	Oct	 2	0:00	0	S
Rule	Halifax	1934	only	-	May	20	0:00	1:00	D
Rule	Halifax	1934	only	-	Sep	16	0:00	0	S
Rule	Halifax	1935	only	-	Jun	 2	0:00	1:00	D
Rule	Halifax	1935	only	-	Sep	30	0:00	0	S
Rule	Halifax	1936	only	-	Jun	 1	0:00	1:00	D
Rule	Halifax	1936	only	-	Sep	14	0:00	0	S
Rule	Halifax	1937	1938	-	May	Sun>=1	0:00	1:00	D
Rule	Halifax	1937	1941	-	Sep	Mon>=24	0:00	0	S
Rule	Halifax	1939	only	-	May	28	0:00	1:00	D
Rule	Halifax	1940	1941	-	May	Sun>=1	0:00	1:00	D
Rule	Halifax	1946	1949	-	Apr	lastSun	2:00	1:00	D
Rule	Halifax	1946	1949	-	Sep	lastSun	2:00	0	S
Rule	Halifax	1951	1954	-	Apr	lastSun	2:00	1:00	D
Rule	Halifax	1951	1954	-	Sep	lastSun	2:00	0	S
Rule	Halifax	1956	1959	-	Apr	lastSun	2:00	1:00	D
Rule	Halifax	1956	1959	-	Sep	lastSun	2:00	0	S
Rule	Halifax	1962	1973	-	Apr	lastSun	2:00	1:00	D
Rule	Halifax	1962	1973	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Halifax	-4:14:24 -	LMT	1902 Jun 15
			-4:00	Halifax	A%sT	1918
			-4:00	Canada	A%sT	1919
			-4:00	Halifax	A%sT	1942 Feb  9  2:00s
			-4:00	Canada	A%sT	1946
			-4:00	Halifax	A%sT	1974
			-4:00	Canada	A%sT
Zone America/Glace_Bay	-3:59:48 -	LMT	1902 Jun 15
			-4:00	Canada	A%sT	1953
			-4:00	Halifax	A%sT	1954
			-4:00	-	AST	1972
			-4:00	Halifax	A%sT	1974
			-4:00	Canada	A%sT

# New Brunswick

# From Paul Eggert (2007-01-31):
# The Time Definition Act <http://www.gnb.ca/0062/PDF-acts/t-06.pdf>
# says they changed at 00:01 through 2006, and
# <http://www.canlii.org/nb/laws/sta/t-6/20030127/whole.html> makes it
# clear that this was the case since at least 1993.
# For now, assume it started in 1993.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Moncton	1933	1935	-	Jun	Sun>=8	1:00	1:00	D
Rule	Moncton	1933	1935	-	Sep	Sun>=8	1:00	0	S
Rule	Moncton	1936	1938	-	Jun	Sun>=1	1:00	1:00	D
Rule	Moncton	1936	1938	-	Sep	Sun>=1	1:00	0	S
Rule	Moncton	1939	only	-	May	27	1:00	1:00	D
Rule	Moncton	1939	1941	-	Sep	Sat>=21	1:00	0	S
Rule	Moncton	1940	only	-	May	19	1:00	1:00	D
Rule	Moncton	1941	only	-	May	 4	1:00	1:00	D
Rule	Moncton	1946	1972	-	Apr	lastSun	2:00	1:00	D
Rule	Moncton	1946	1956	-	Sep	lastSun	2:00	0	S
Rule	Moncton	1957	1972	-	Oct	lastSun	2:00	0	S
Rule	Moncton	1993	2006	-	Apr	Sun>=1	0:01	1:00	D
Rule	Moncton	1993	2006	-	Oct	lastSun	0:01	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Moncton	-4:19:08 -	LMT	1883 Dec  9
			-5:00	-	EST	1902 Jun 15
			-4:00	Canada	A%sT	1933
			-4:00	Moncton	A%sT	1942
			-4:00	Canada	A%sT	1946
			-4:00	Moncton	A%sT	1973
			-4:00	Canada	A%sT	1993
			-4:00	Moncton	A%sT	2007
			-4:00	Canada	A%sT

# Quebec

# From Paul Eggert (2020-01-10):
# See America/Toronto for most of Quebec, including Montreal.
# See America/Halifax for the Îles de la Madeleine and the Listuguj reserve.
# See America/Puerto_Rico for east of Natashquan.

# Ontario

# From Mark Brader (2003-07-26):
# [According to the Toronto Star] Orillia, Ontario, adopted DST
# effective Saturday, 1912-06-22, 22:00; the article mentions that
# Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
# have already done so.  In Orillia DST was to run until Saturday,
# 1912-08-31 (no time mentioned), but it was met with considerable
# hostility from certain segments of the public, and was revoked after
# only two weeks - I copied it as Saturday, 1912-07-07, 22:00, but
# presumably that should be -07-06.  (1912-06-19, -07-12; also letters
# earlier in June).
#
# Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
#
# From Paul Eggert (2017-07-08):
# For more on Orillia, see: Daubs K. Bold attempt at daylight saving
# time became a comic failure in Orillia. Toronto Star 2017-07-08.
# https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
# From Paul Eggert (2025-03-20):
# Also see the 1912-06-17 front page of The Evening Sunbeam,
# reproduced in: Richardson M. "Daylight saving was a confusing
# time in Orillia" in the 2025-03-15 Orillia Matters. Richardson writes,
# "The first Sunday after the switch was made, [DST proponent and
# Orillia mayor William Sword] Frost walked into church an hour late.
# This became a symbol of the downfall of daylight saving in Orillia."
# The mayor became known as "Daylight Bill".
# https://www.orilliamatters.com/local-news/column-daylight-saving-was-a-confusing-time-in-orillia-10377529

# From Mark Brader (2010-03-06):
#
# In the (Toronto) Globe and Mail for Saturday, 1955-09-24, in the bottom
# right corner of page 1, it says that Toronto will return to standard
# time at 2 am Sunday morning (which agrees with the database), and that:
#
#     The one-hour setback will go into effect throughout most of Ontario,
#     except in areas like Windsor which remains on standard time all year.
#
# ... I don't know if Windsor began observing DST when Detroit did,
# or in 1974, or on some other date.
#
# By the way, the article continues by noting that:
#
#     Some cities in the United States have pushed the deadline back
#     three weeks and will change over from daylight saving in October.

# From Chris Walton (2024-01-09):
# The [Toronto] changes in 1947, 1948, and 1949 took place at 2:00 a.m. local
# time instead of midnight....  Toronto Daily Star - ...
# April 2, 1947 - Page 39 ... April 7, 1948 - Page 13 ...
# April 2, 1949 - Page 1 ... April 7, 1949 - Page 24 ...
# November 25, 1949 - Page 52 ... April 21, 1950 - Page 14 ...
# September 19, 1950 - Page 46 ... September 20, 1950 - Page 3 ...
# November 24, 1950 - Page 21

# From Arthur David Olson (2010-07-17):
#
# "Standard Time and Time Zones in Canada" appeared in
# The Journal of The Royal Astronomical Society of Canada,
# volume 26, number 2 (February 1932) and, as of 2010-07-17,
# was available at
# http://adsabs.harvard.edu/full/1932JRASC..26...49S
#
# It includes the text below (starting on page 57):
#
#   A list of the places in Canada using daylight saving time would
# require yearly revision. From information kindly furnished by
# the provincial governments and by the postmasters in many cities
# and towns, it is found that the following places used daylight sav-
# ing in 1930. The information for the province of Quebec is definite,
# for the other provinces only approximate:
#
#	Province	Daylight saving time used
# Prince Edward Island	Not used.
# Nova Scotia		In Halifax only.
# New Brunswick		In St. John only.
# Quebec		In the following places:
#			Montreal	Lachine
#			Quebec		Mont-Royal
#			Lévis		Iberville
#			St. Lambert	Cap de la Madelèine
#			Verdun		Loretteville
#			Westmount	Richmond
#			Outremont	St. Jérôme
#			Longueuil	Greenfield Park
#			Arvida		Waterloo
#			Chambly-Canton	Beaulieu
#			Melbourne	La Tuque
#			St. Théophile	Buckingham
# Ontario		Used generally in the cities and towns along
#			the southerly part of the province. Not
#			used in the northwesterly part.
# Manitoba		Not used.
# Saskatchewan		In Regina only.
# Alberta		Not used.
# British Columbia	Not used.
#
#   With some exceptions, the use of daylight saving may be said to be limited
# to those cities and towns lying between Quebec city and Windsor, Ont.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Toronto	1919	only	-	Mar	30	23:30	1:00	D
Rule	Toronto	1919	only	-	Oct	26	0:00	0	S
Rule	Toronto	1920	only	-	May	 2	2:00	1:00	D
Rule	Toronto	1920	only	-	Sep	26	0:00	0	S
Rule	Toronto	1921	only	-	May	15	2:00	1:00	D
Rule	Toronto	1921	only	-	Sep	15	2:00	0	S
Rule	Toronto	1922	1923	-	May	Sun>=8	2:00	1:00	D
# Shanks & Pottenger say 1923-09-19; assume it's a typo and that "-16"
# was meant.
Rule	Toronto	1922	1926	-	Sep	Sun>=15	2:00	0	S
Rule	Toronto	1924	1927	-	May	Sun>=1	2:00	1:00	D
Rule	Toronto	1927	1937	-	Sep	Sun>=25	2:00	0	S
Rule	Toronto	1928	1937	-	Apr	Sun>=25	2:00	1:00	D
Rule	Toronto	1938	1940	-	Apr	lastSun	2:00	1:00	D
Rule	Toronto	1938	1939	-	Sep	lastSun	2:00	0	S
Rule	Toronto	1945	1948	-	Sep	lastSun	2:00	0	S
Rule	Toronto	1946	1973	-	Apr	lastSun	2:00	1:00	D
Rule	Toronto	1949	1950	-	Nov	lastSun	2:00	0	S
Rule	Toronto	1951	1956	-	Sep	lastSun	2:00	0	S
# Shanks & Pottenger say Toronto ended DST a week early in 1971,
# namely on 1971-10-24, but Mark Brader wrote (2003-05-31) that this
# is wrong, and that he had confirmed it by checking the 1971-10-30
# Toronto Star, which said that DST was ending 1971-10-31 as usual.
Rule	Toronto	1957	1973	-	Oct	lastSun	2:00	0	S

# The Bahamas match Toronto since 1970.

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Toronto	-5:17:32 -	LMT	1895
			-5:00	Canada	E%sT	1919
			-5:00	Toronto	E%sT	1942 Feb  9  2:00s
			-5:00	Canada	E%sT	1946
			-5:00	Toronto	E%sT	1974
			-5:00	Canada	E%sT
# For Atikokan see America/Panama.


# Manitoba

# From Rob Douglas (2006-04-06):
# the old Manitoba Time Act - as amended by Bill 2, assented to
# March 27, 1987 ... said ...
# "between two o'clock Central Standard Time in the morning of
# the first Sunday of April of each year and two o'clock Central
# Standard Time in the morning of the last Sunday of October next
# following, one hour in advance of Central Standard Time."...
# I believe that the English legislation [of the old time act] had
# been assented to (March 22, 1967)....
# Also, as far as I can tell, there was no order-in-council varying
# the time of Daylight Saving Time for 2005 and so the provisions of
# the 1987 version would apply - the changeover was at 2:00 Central
# Standard Time (i.e. not until 3:00 Central Daylight Time).

# From Paul Eggert (2006-04-10):
# Shanks & Pottenger say Manitoba switched at 02:00 (not 02:00s)
# starting 1966.  Since 02:00s is clearly correct for 1967 on, assume
# it was also 02:00s in 1966.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Winn	1916	only	-	Apr	23	0:00	1:00	D
Rule	Winn	1916	only	-	Sep	17	0:00	0	S
Rule	Winn	1918	only	-	Apr	14	2:00	1:00	D
Rule	Winn	1918	only	-	Oct	27	2:00	0	S
Rule	Winn	1937	only	-	May	16	2:00	1:00	D
Rule	Winn	1937	only	-	Sep	26	2:00	0	S
Rule	Winn	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	Winn	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	Winn	1945	only	-	Sep	lastSun	2:00	0	S
Rule	Winn	1946	only	-	May	12	2:00	1:00	D
Rule	Winn	1946	only	-	Oct	13	2:00	0	S
Rule	Winn	1947	1949	-	Apr	lastSun	2:00	1:00	D
Rule	Winn	1947	1949	-	Sep	lastSun	2:00	0	S
Rule	Winn	1950	only	-	May	 1	2:00	1:00	D
Rule	Winn	1950	only	-	Sep	30	2:00	0	S
Rule	Winn	1951	1960	-	Apr	lastSun	2:00	1:00	D
Rule	Winn	1951	1958	-	Sep	lastSun	2:00	0	S
Rule	Winn	1959	only	-	Oct	lastSun	2:00	0	S
Rule	Winn	1960	only	-	Sep	lastSun	2:00	0	S
Rule	Winn	1963	only	-	Apr	lastSun	2:00	1:00	D
Rule	Winn	1963	only	-	Sep	22	2:00	0	S
Rule	Winn	1966	1986	-	Apr	lastSun	2:00s	1:00	D
Rule	Winn	1966	2005	-	Oct	lastSun	2:00s	0	S
Rule	Winn	1987	2005	-	Apr	Sun>=1	2:00s	1:00	D
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Winnipeg	-6:28:36 -	LMT	1887 Jul 16
			-6:00	Winn	C%sT	2006
			-6:00	Canada	C%sT


# Saskatchewan

# From Mark Brader (2003-07-26):
# The first actual adoption of DST in Canada was at the municipal
# level.  As the [Toronto] Star put it (1912-06-07), "While people
# elsewhere have long been talking of legislation to save daylight,
# the city of Moose Jaw [Saskatchewan] has acted on its own hook."
# DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
# presumably late evening, as below), and would run until "the end of
# the summer".  The discrepancy between municipal time and railroad
# time was noted.

# From Paul Eggert (2003-07-27):
# Willett (1914-03) notes that DST "has been in operation ... in the
# City of Moose Jaw, Saskatchewan, for one year."

# From Paul Eggert (2019-07-25):
# Pearce's book says Regina observed DST in 1914-1917.  No dates and times,
# unfortunately.  It also says that in 1914 Saskatoon observed DST
# from 1 June to 6 July, and that DST was also tried out in Davidson,
# Melfort, and Prince Albert.

# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that since 1970 this region has mostly been as Regina.
# Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
# Other western towns (e.g. Lloydminster) are like Edmonton.
# Matthews and Vincent (1998) write that Denare Beach and Creighton
# are like Winnipeg, in violation of Saskatchewan law.

# From W. Jones (1992-11-06):
# The. . .below is based on information I got from our law library, the
# provincial archives, and the provincial Community Services department.
# A precise history would require digging through newspaper archives, and
# since you didn't say what you wanted, I didn't bother.
#
# Saskatchewan is split by a time zone meridian (105W) and over the years
# the boundary became pretty ragged as communities near it reevaluated
# their affiliations in one direction or the other.  In 1965 a provincial
# referendum favoured legislating common time practices.
#
# On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
# Saskatchewan 1978) was proclaimed, and established that the eastern
# part of Saskatchewan would use CST year round, that districts in
# northwest Saskatchewan would by default follow CST but could opt to
# follow Mountain Time rules (thus 1 hour difference in the winter and
# zero in the summer), and that districts in southwest Saskatchewan would
# by default follow MT but could opt to follow CST.
#
# It took a few years for the dust to settle (I know one story of a town
# on one time zone having its school in another, such that a mom had to
# serve her family lunch in two shifts), but presently it seems that only
# a few towns on the border with Alberta (e.g. Lloydminster) follow MT
# rules any more; all other districts appear to have used CST year round
# since sometime in the 1960s.

# From Chris Walton (2006-06-26):
# The Saskatchewan time act which was last updated in 1996 is about 30 pages
# long and rather painful to read.
# http://www.qp.gov.sk.ca/documents/English/Statutes/Statutes/T14.pdf

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Regina	1918	only	-	Apr	14	2:00	1:00	D
Rule	Regina	1918	only	-	Oct	27	2:00	0	S
Rule	Regina	1930	1934	-	May	Sun>=1	0:00	1:00	D
Rule	Regina	1930	1934	-	Oct	Sun>=1	0:00	0	S
Rule	Regina	1937	1941	-	Apr	Sun>=8	0:00	1:00	D
Rule	Regina	1937	only	-	Oct	Sun>=8	0:00	0	S
Rule	Regina	1938	only	-	Oct	Sun>=1	0:00	0	S
Rule	Regina	1939	1941	-	Oct	Sun>=8	0:00	0	S
Rule	Regina	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	Regina	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	Regina	1945	only	-	Sep	lastSun	2:00	0	S
Rule	Regina	1946	only	-	Apr	Sun>=8	2:00	1:00	D
Rule	Regina	1946	only	-	Oct	Sun>=8	2:00	0	S
Rule	Regina	1947	1957	-	Apr	lastSun	2:00	1:00	D
Rule	Regina	1947	1957	-	Sep	lastSun	2:00	0	S
Rule	Regina	1959	only	-	Apr	lastSun	2:00	1:00	D
Rule	Regina	1959	only	-	Oct	lastSun	2:00	0	S
#
Rule	Swift	1957	only	-	Apr	lastSun	2:00	1:00	D
Rule	Swift	1957	only	-	Oct	lastSun	2:00	0	S
Rule	Swift	1959	1961	-	Apr	lastSun	2:00	1:00	D
Rule	Swift	1959	only	-	Oct	lastSun	2:00	0	S
Rule	Swift	1960	1961	-	Sep	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Regina	-6:58:36 -	LMT	1905 Sep
			-7:00	Regina	M%sT	1960 Apr lastSun  2:00
			-6:00	-	CST
Zone America/Swift_Current -7:11:20 -	LMT	1905 Sep
			-7:00	Canada	M%sT	1946 Apr lastSun  2:00
			-7:00	Regina	M%sT	1950
			-7:00	Swift	M%sT	1972 Apr lastSun  2:00
			-6:00	-	CST


# Alberta

# From Alois Treindl (2019-07-19):
# There was no DST in Alberta in 1967... Calgary Herald, 29 April 1967.
# 1969, no DST, from Edmonton Journal 18 April 1969
#
# From Paul Eggert (2019-07-25):
# Pearce's book says that Alberta's 1948 Daylight Saving Act required
# Mountain Standard Time without DST, and that "anyone who broke that law
# could be fined up to $25 and costs".  There seems to be no record of
# anybody paying the fine.  The law was not changed until an August 1971
# plebiscite reinstituted DST in 1972.  This story is also mentioned in:
# Boyer JP. Forcing Choice: The Risky Reward of Referendums. Dundum. 2017.
# ISBN 978-1459739123.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Edm	1918	1919	-	Apr	Sun>=8	2:00	1:00	D
Rule	Edm	1918	only	-	Oct	27	2:00	0	S
Rule	Edm	1919	only	-	May	27	2:00	0	S
Rule	Edm	1920	1923	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1920	only	-	Oct	lastSun	2:00	0	S
Rule	Edm	1921	1923	-	Sep	lastSun	2:00	0	S
Rule	Edm	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	Edm	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	Edm	1945	only	-	Sep	lastSun	2:00	0	S
Rule	Edm	1947	only	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1947	only	-	Sep	lastSun	2:00	0	S
Rule	Edm	1972	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1972	2006	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Edmonton	-7:33:52 -	LMT	1906 Sep
			-7:00	Edm	M%sT	1987
			-7:00	Canada	M%sT


# British Columbia

# From Paul Eggert (2006-03-22):
# Shanks & Pottenger write that since 1970 most of this region has
# been like Vancouver.
# Dawson Creek uses MST.  Much of east BC is like Edmonton.

# From Matt Johnson (2015-09-21):
# Fort Nelson, BC, Canada will cancel DST this year.  So while previously they
# were aligned with America/Vancouver, they're now aligned with
# America/Dawson_Creek.
# http://www.northernrockies.ca/EN/meta/news/archives/2015/northern-rockies-time-change.html
#
# From Tim Parenti (2015-09-23):
# This requires a new zone for the Northern Rockies Regional Municipality,
# America/Fort_Nelson.  The resolution of 2014-12-08 was reached following a
# 2014-11-15 poll with nearly 75% support.  Effectively, the municipality has
# been on MST (-0700) like Dawson Creek since it advanced its clocks on
# 2015-03-08.
#
# From Paul Eggert (2019-07-25):
# Shanks says Fort Nelson did not observe DST in 1946, unlike Vancouver.
# Alois Treindl confirmed this on 07-22, citing the 1946-04-27 Vancouver Daily
# Province.  He also cited the 1946-09-28 Victoria Daily Times, which said
# that Vancouver, Victoria, etc. "change at midnight Saturday"; for now,
# guess they meant 02:00 Sunday since 02:00 was common practice in Vancouver.
#
# Early Vancouver, Volume Four, by Major J.S. Matthews, V.D., 2011 edition
# says that a 1922 plebiscite adopted DST, but a 1923 plebiscite rejected it.
# http://former.vancouver.ca/ctyclerk/archives/digitized/EarlyVan/SearchEarlyVan/Vol4pdf/MatthewsEarlyVancouverVol4_DaylightSavings.pdf
# A catalog entry for a newspaper clipping seems to indicate that Vancouver
# observed DST in 1941 from 07-07 through 09-27; see
# https://searcharchives.vancouver.ca/daylight-saving-1918-starts-again-july-7-1941-start-d-s-sept-27-end-of-d-s-1941
# We have no further details, so omit them for now.

# From Arthur David Olson (2026-03-02):
# B. C. Gov News: “Adopting permanent daylight saving time: ‘Spring forward’
# on March 8 will be the last time change, ending twice-yearly clock changes.”
# https://news.gov.bc.ca/releases/2026AG0013-000209
#
# From Paul Eggert (2026-03-07):
# The law says that 21 hours after the usual 2026-03-08 02:00 switch from
# PST to PDT, the next day inaugurates the new standard time Pacific Time,
# i.e., just one clock change but two name changes separated by 21 hours.
# PT, the obvious abbreviation for Pacific Time, is one letter too short
# to conform to TZDB’s (and POSIX’s) [-+[:alnum:]]{3,6} requirements.
# I asked the BC government for advice, with no response. For now, do this:
#   1.	As a temporary hack, pretend that the BC law takes effect
#	not on 2026-03-09 at 00:00, but on 2026-11-01 at 02:00.
#	This pretense works around a limitation in CLDR v48.2 (2026-03-17),
#	which would otherwise say the interval uses “Pacific Standard Time”.
#	(Below, this temporary hack is marked “Temporary hack; see above.”)
#	Strictly speaking this hack is incorrect since the interval uses
#	standard time, but it does have the right UT offset and it
#	works around the CLDR limitation.  We should be able to remove
#	the temporary hack after CLDR is fixed.
#   2.	After the BC law takes effect, model the time as MST sans DST.
#	We can change this later if another conforming non-numeric abbreviation
#	for Pacific Time becomes more popular.  Possibilities include:
#   MST - the most compatible with existing software and practice,
#	and already used in parts of BC and in Yukon
#   PDT - almost as software-friendly, but confusing because it implies
#	it is DST and is paired with PST, whereas PT is standard time
#   PST - straightforward but even more confusing,
#	and will likely break much software that assumes PST is -08
#   -07 - accurate and clear in itself, but makes BC look odd vs neighbors
#   CPT, CPST - for Canadian Pacific (Standard) Time,
#	by analogy with AEST in Australia
#   P-T - conforming approximation to “PT”
#   PT+ - like P-T but suggesting one-hour advance over PST

# From Chris Walton (2026-03-15):
# The Regional District of East Kootenay is planning to move to year-round
# Mountain Standard Time (MST) on November 1, 2026....
# https://www.rdek.bc.ca/news/entry/rdek_board_moves_to_transition_to_year_round_mountain_standard_time
# (2026-03-17):
# The final decision East Kootenay made a few days ago may turn out not to
# be final after all. They are going to reopen the debate next month!
# https://www.cbc.ca/news/canada/british-columbia/what-time-is-it-in-the-east-kootenay-debate-9.7132624
# From Paul Eggert (2026-03-17):
# Mayor Steve Fairbairn of Elkford asked the question be called a second time,
# saying, “Pardon the pun, but this is not a time-sensitive issue.”
# For now, merely mention the potential change in these comments.
# If it happens it would likely affect clocks starting 2027-03-14 at 02:00.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Vanc	1918	only	-	Apr	14	2:00	1:00	D
Rule	Vanc	1918	only	-	Oct	27	2:00	0	S
Rule	Vanc	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	Vanc	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	Vanc	1945	only	-	Sep	30	2:00	0	S
Rule	Vanc	1946	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Vanc	1946	only	-	Sep	29	2:00	0	S
Rule	Vanc	1947	1961	-	Sep	lastSun	2:00	0	S
Rule	Vanc	1962	2006	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Vancouver	-8:12:28 -	LMT	1884
			-8:00	Vanc	P%sT	1987
			-8:00	Canada	P%sT	2026 Mar  9
			# Temporary hack; see above.
			-8:00	1:00	PDT	2026 Nov  1 02:00
			# End of temporary hack.
			-7:00	-	MST
Zone America/Dawson_Creek -8:00:56 -	LMT	1884
			-8:00	Canada	P%sT	1947
			-8:00	Vanc	P%sT	1972 Aug 30  2:00
			-7:00	-	MST
Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
			-8:00	Vanc	P%sT	1946
			-8:00	-	PST	1947
			-8:00	Vanc	P%sT	1987
			-8:00	Canada	P%sT	2015 Mar  8  2:00
			-7:00	-	MST
# For Creston see America/Phoenix.

# Northwest Territories, Nunavut, Yukon

# From Chris Walton (2022-11-06):
# Whitehorse Star - Thursday April 22, 1965 - page 1
# title: DST Starts Monday ...
# https://www.newspapers.com/image/578587481/
# The title of this first article is wrong and/or misleading.
# Also, the start time shown in the  article is vague; it simply says "after
# midnight" when it probably should have stated 2:00a.m....
#
# Whitehorse Star - Monday October 25, 1965 - page 15 ...
# https://www.newspapers.com/image/578589147/
# The 1965 Yukon Council minutes can be found here:
# http://assets.yukonarchives.ca/PER_YG_06_1965_C20_S02_v1.pdf
# ... I do not currently believe that NWT touched any of its clocks in 1965....
#
# Whitehorse Star - Thursday Feb 24,1966 - page 2
# title: It's Time for YDT ...
# https://www.newspapers.com/image/578575979/ ...
# America/Whitehorse as a permanent change from UTC-9(YST) to
# UTC-8(PST) at 00:00 on Sunday February 27, 1966....
#
# Whitehorse Star - Friday April 28,1972 - page 6
# title: Daylight Saving Time for N.W.T....
# https://www.newspapers.com/image/578701610/ ...
# Nunavut and NWT zones ... DST starting in 1972.... Start and End ...
# should be the same as the rest of Canada
#
#
# From Paul Eggert (2022-11-06):
# For now, assume Yukon's 1965-04-22 spring forward was 00:00 -> 02:00, as this
# seems likely than 02:00 -> 04:00 and matches "after midnight".

# From Paul Eggert (2006-03-22):
# Dawson switched to PST in 1973.  Inuvik switched to MST in 1979.
# Mathew Englander (1996-10-07) gives the following refs:
#	* 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
#	c. 7 defines Yukon standard time as UTC-9....
#	see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
#	[https://www.canlii.org/en/ca/laws/stat/rsc-1985-c-i-21/latest/rsc-1985-c-i-21.html]
#	* C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
#	* O.I.C. 1980/02 established DST.
#	* O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.

# From Brian Inglis (2015-04-14):
#
# I tried to trace the history of Yukon time and found the following
# regulations, giving the reference title and URL if found, regulation name,
# and relevant quote if available.  Each regulation specifically revokes its
# predecessor.  The final reference is to the current Interpretation Act
# authorizing and resulting from these regulatory changes.
#
# Only recent regulations were retrievable via Yukon government site search or
# index, and only some via Canadian legal sources.  Other sources used include
# articles titled "Standard Time and Time Zones in Canada" from JRASC via ADS
# Abstracts, cited by ADO for 1932 ..., and updated versions from 1958 and
# 1970 quoted below; each article includes current extracts from provincial
# and territorial ST and DST regulations at the end, summaries and details of
# standard times and daylight saving time at many locations across Canada,
# with time zone maps, tables and calculations for Canadian Sunrise, Sunset,
# and LMST; they also cover many countries and global locations, with a chart
# and table showing current Universal Time offsets, and may be useful as
# another source of information for 1970 and earlier.
#
# * Standard Time and Time Zones in Canada; Smith, C.C.; JRASC, Vol. 26,
#   pp.49-77; February 1932; SAO/NASA Astrophysics Data System (ADS)
#   http://adsabs.harvard.edu/abs/1932JRASC..26...49S from p.75:
#   Yukon Interpretation Ordinance
#   Yukon standard time is the local mean time at the one hundred and
#   thirty-fifth meridian.
#
# * Standard Time and Time Zones in Canada; Smith, C.C.; Thomson, Malcolm M.;
#   JRASC, Vol. 52, pp.193-223; October 1958; SAO/NASA Astrophysics Data System
#   (ADS) http://adsabs.harvard.edu/abs/1958JRASC..52..193S from pp.220-1:
#   Yukon Interpretation Ordinance, 1955, Chap. 16.
#
#     (1) Subject to this section, standard time shall be reckoned as nine
#     hours behind Greenwich Time and called Yukon Standard Time.
#
#     (2) Notwithstanding subsection (1), the Commissioner may make regulations
#     varying the manner of reckoning standard time.
#
# * Yukon Territory Commissioner's Order 1966-20 Interpretation Ordinance
#   [no online source found]
#
# * Standard Time and Time Zones in Canada; Thomson, Malcolm M.; JRASC,
#   Vol. 64, pp.129-162; June 1970; SAO/NASA Astrophysics Data System (ADS)
#   http://adsabs.harvard.edu/abs/1970JRASC..64..129T from p.156: Yukon
#   Territory Commissioner's Order 1967-59 Interpretation Ordinance ...
#
#     1. Commissioner's Order 1966-20 dated at Whitehorse in the Yukon
#     Territory on 27th January, 1966, is hereby revoked.
#
#     2. Yukon (East) Standard Time as defined by section 36 of the
#     Interpretation Ordinance from and after mid-night on the 28th day of May,
#     1967 shall be reckoned in the same manner as Pacific Standard Time, that
#     is to say, eight hours behind Greenwich Time in the area of the Yukon
#     Territory lying east of the 138th degree longitude west.
#
#     3. In the remainder of the Territory, lying west of the 138th degree
#     longitude west, Yukon (West) Standard Time shall be reckoned as nine
#     hours behind Greenwich Time.
#
# * Yukon Standard Time defined as Pacific Standard Time, YCO 1973/214
#   https://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
#   C.O. 1973/214 INTERPRETATION ACT ...
#
#     1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
#     revoked.
#
#     2. Yukon Standard Time as defined by section 36 of the Interpretation
#     Act from and after midnight on the twenty-eighth day of October, 1973
#     shall be reckoned in the same manner as Pacific Standard Time, that is
#     to say eight hours behind Greenwich Time.
#
# * O.I.C. 1980/02 INTERPRETATION ACT
#   https://mm.icann.org/pipermail/tz/attachments/20201125/d5adc93b/CAYTOIC1980-02DST1980-01-04-0001.pdf
#
# * Yukon Daylight Saving Time, YOIC 1987/56
#   https://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
#   O.I.C. 1987/056 INTERPRETATION ACT ...
#
#   In every year between
#     (a) two o'clock in the morning in the first Sunday in April, and
#     (b) two o'clock in the morning in the last Sunday in October,
#   Standard Time shall be reckoned as seven hours behind Greenwich Time and
#   called Yukon Daylight Saving Time.
#   ...
#   Dated ... 9th day of March, A.D., 1987.
#
# * Yukon Daylight Saving Time 2006, YOIC 2006/127
#   https://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
#   O.I.C. 2006/127 INTERPRETATION ACT ...
#
#     1. In Yukon each year the time for general purposes shall be 7 hours
#     behind Greenwich mean time during the period commencing at two o'clock
#     in the forenoon on the second Sunday of March and ending at two o'clock
#     in the forenoon on the first Sunday of November and shall be called
#     Yukon Daylight Saving Time.
#
#     2. Order-in-Council 1987/56 is revoked.
#
#     3. This order comes into force January 1, 2007.
#
# * Interpretation Act, RSY 2002, c 125
# https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html

# From Chris Walton (2022-11-06):
# The 5th edition of the Atlas of Canada contains a time zone map that
# shows both legislated and observed time zone boundaries.
# All communities on Baffin Island are shown to be observing Eastern time.
# The date on the map is 1984.
# https://ftp.maps.canada.ca/pub/nrcan_rncan/raster/atlas_5_ed/eng/other/referencemaps/mcr4056.pdf

# From Rives McDow (1999-09-04):
# Nunavut ... moved ... to incorporate the whole territory into one time zone.
# Nunavut moves to single time zone Oct. 31
# http://www.nunatsiaq.com/nunavut/nvt90903_13.html

# From Paul Eggert (1999-09-20):
# Basic Facts: The New Territory
# http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html
# (1999) reports that ... Coral Harbour does not observe DST.

# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) say the following, but we lack histories
# for these potential new Zones.
#
# The Canadian Forces station at Alert uses Eastern Time while the
# handful of residents at the Eureka weather station [in the Central
# zone] skip daylight savings.  Baffin Island, which is crossed by the
# Central, Eastern and Atlantic Time zones only uses Eastern Time.
# Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
# Central Time and Southampton Island [in the Central zone] is not
# required to use daylight savings.

# From <http://www.nunatsiaqonline.ca/archives/nunavut001130/nvt21110_02.html>
# Nunavut now has two time zones (2000-11-10):
# The Nunavut government would allow its employees in Kugluktuk and
# Cambridge Bay to operate on central time year-round, putting them
# one hour behind the rest of Nunavut for six months during the winter.
# At the end of October the two communities had rebelled against
# Nunavut's unified time zone, refusing to shift to eastern time with
# the rest of the territory for the winter.  Cambridge Bay remained on
# central time, while Kugluktuk, even farther west, reverted to
# mountain time, which they had used before the advent of Nunavut's
# unified time zone in 1999.
#
# From Rives McDow (2001-01-20), quoting the Nunavut government:
# The preceding decision came into effect at midnight, Saturday Nov 4, 2000.

# From Paul Eggert (2000-12-04):
# Let's just keep track of the official times for now.

# From Rives McDow (2001-03-07):
# The premier of Nunavut has issued a ministerial statement advising
# that effective 2001-04-01, the territory of Nunavut will revert
# back to three time zones (mountain, central, and eastern).  Of the
# cities in Nunavut, Coral Harbor is the only one that I know of that
# has said it will not observe dst, staying on EST year round.  I'm
# checking for more info, and will get back to you if I come up with
# more.
# [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]

# From Gwillim Law (2005-05-21):
# According to ...
# http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp
# (from a 1998 Canadian Geographic article), the de facto and de jure time
# for Southampton Island (at the north end of Hudson Bay) is UTC-5 all year
# round.  Using Google, it's easy to find other websites that confirm this.
# I wasn't able to find how far back this time regimen goes, but since it
# predates the creation of Nunavut, it probably goes back many years....
# The Inuktitut name of Coral Harbour is Sallit, but it's rarely used.
#
# From Paul Eggert (2014-10-17):
# For lack of better information, assume that Southampton Island observed
# daylight saving only during wartime.  Gwillim Law's email also
# mentioned maps now maintained by National Research Council Canada;
# see above for an up-to-date link.

# From Chris Walton (2007-03-01):
# ... the community of Resolute (located on Cornwallis Island in
# Nunavut) moved from Central Time to Eastern Time last November.
# Basically the community did not change its clocks at the end of
# daylight saving....
# http://www.nnsl.com/frames/newspapers/2006-11/nov13_06none.html

# From Chris Walton (2011-03-21):
# Back in 2007 I initiated the creation of a new "zone file" for Resolute
# Bay. Resolute Bay is a small community located about 900km north of
# the Arctic Circle. The zone file was required because Resolute Bay had
# decided to use UTC-5 instead of UTC-6 for the winter of 2006-2007.
#
# According to new information which I received last week, Resolute Bay
# went back to using UTC-6 in the winter of 2007-2008...
#
# On March 11/2007 most of Canada went onto daylight saving. On March
# 14/2007 I phoned the Resolute Bay hamlet office to do a "time check." I
# talked to somebody that was both knowledgeable and helpful. I was able
# to confirm that Resolute Bay was still operating on UTC-5. It was
# explained to me that Resolute Bay had been on the Eastern Time zone
# (EST) in the winter, and was now back on the Central Time zone (CDT).
# i.e. the time zone had changed twice in the last year but the clocks
# had not moved. The residents had to know which time zone they were in
# so they could follow the correct TV schedule...
#
# On Nov 02/2008 most of Canada went onto standard time. On Nov 03/2008 I
# phoned the Resolute Bay hamlet office...[D]ue to the challenging nature
# of the phone call, I decided to seek out an alternate source of
# information. I found an e-mail address for somebody by the name of
# Stephanie Adams whose job was listed as "Inns North Support Officer for
# Arctic Co-operatives." I was under the impression that Stephanie lived
# and worked in Resolute Bay...
#
# On March 14/2011 I phoned the hamlet office again. I was told that
# Resolute Bay had been using Central Standard Time over the winter of
# 2010-2011 and that the clocks had therefore been moved one hour ahead
# on March 13/2011. The person I talked to was aware that Resolute Bay
# had previously experimented with Eastern Standard Time but he could not
# tell me when the practice had stopped.
#
# On March 17/2011 I searched the Web to find an e-mail address of
# somebody that might be able to tell me exactly when Resolute Bay went
# off Eastern Standard Time. I stumbled on the name "Aziz Kheraj." Aziz
# used to be the mayor of Resolute Bay and he apparently owns half the
# businesses including "South Camp Inn." This website has some info on
# Aziz:
# http://www.uphere.ca/node/493
#
# I sent Aziz an e-mail asking when Resolute Bay had stopped using
# Eastern Standard Time.
#
# Aziz responded quickly with this: "hi, The time was not changed for the
# 1 year only, the following year, the community went back to the old way
# of "spring ahead-fall behind" currently we are zulu plus 5 hrs and in
# the winter Zulu plus 6 hrs"
#
# This of course conflicted with everything I had ascertained in November 2008.
#
# I sent Aziz a copy of my 2008 e-mail exchange with Stephanie. Aziz
# responded with this: "Hi, Stephanie lives in Winnipeg. I live here, You
# may want to check with the weather office in Resolute Bay or do a
# search on the weather through Env. Canada. web site"
#
# If I had realized the Stephanie did not live in Resolute Bay I would
# never have contacted her.  I now believe that all the information I
# obtained in November 2008 should be ignored...
# I apologize for reporting incorrect information in 2008.

# From Tim Parenti (2020-03-05):
# The government of Yukon announced [yesterday] the cessation of seasonal time
# changes.  "After clocks are pushed ahead one hour on March 8, the territory
# will remain on [UTC-07].  ... [The government] found 93 per cent of
# respondents wanted to end seasonal time changes and, of that group, 70 per
# cent wanted 'permanent Pacific Daylight Saving Time.'"
# https://www.cbc.ca/news/canada/north/yukon-end-daylight-saving-time-1.5486358
#
# Although the government press release prefers PDT, we prefer MST for
# consistency with nearby Dawson Creek, Creston, and Fort Nelson.
# https://yukon.ca/en/news/yukon-end-seasonal-time-change

# From Andrew G. Smith (2020-09-24):
# Yukon has completed its regulatory change to be on UTC -7 year-round....
# http://www.gov.yk.ca/legislation/regs/oic2020_125.pdf
# What we have done is re-defined Yukon Standard Time, as we are
# authorized to do under section 33 of our Interpretation Act:
# http://www.gov.yk.ca/legislation/acts/interpretation_c.pdf
#
# From Paul Eggert (2020-09-24):
# tzdb uses the obsolete YST abbreviation for standard time in Yukon through
# about 1970, and uses PST for standard time in Yukon since then.  Consistent
# with that, use MST for -07, the new standard time in Yukon effective Nov. 1.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	NT_YK	1918	only	-	Apr	14	2:00	1:00	D
Rule	NT_YK	1918	only	-	Oct	27	2:00	0	S
Rule	NT_YK	1919	only	-	May	25	2:00	1:00	D
Rule	NT_YK	1919	only	-	Nov	 1	0:00	0	S
Rule	NT_YK	1942	only	-	Feb	 9	2:00	1:00	W # War
Rule	NT_YK	1945	only	-	Aug	14	23:00u	1:00	P # Peace
Rule	NT_YK	1945	only	-	Sep	30	2:00	0	S
Rule	NT_YK	1972	1986	-	Apr	lastSun	2:00	1:00	D
Rule	NT_YK	1972	2006	-	Oct	lastSun	2:00	0	S
Rule	NT_YK	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
Rule	Yukon	1965	only	-	Apr	lastSun	0:00	2:00	DD
Rule	Yukon	1965	only	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
# formerly Frobisher Bay
Zone America/Iqaluit	0	-	-00	1942 Aug # Frobisher Bay est.
			-5:00	NT_YK	E%sT	1999 Oct 31  2:00
			-6:00	Canada	C%sT	2000 Oct 29  2:00
			-5:00	Canada	E%sT
# aka Qausuittuq
Zone America/Resolute	0	-	-00	1947 Aug 31 # Resolute founded
			-6:00	NT_YK	C%sT	2000 Oct 29  2:00
			-5:00	-	EST	2001 Apr  1  3:00
			-6:00	Canada	C%sT	2006 Oct 29  2:00
			-5:00	-	EST	2007 Mar 11  3:00
			-6:00	Canada	C%sT
# aka Kangiqiniq
Zone America/Rankin_Inlet 0	-	-00	1957 # Rankin Inlet founded
			-6:00	NT_YK	C%sT	2000 Oct 29  2:00
			-5:00	-	EST	2001 Apr  1  3:00
			-6:00	Canada	C%sT
# aka Iqaluktuuttiaq
Zone America/Cambridge_Bay 0	-	-00	1920 # trading post est.?
			-7:00	NT_YK	M%sT	1999 Oct 31  2:00
			-6:00	Canada	C%sT	2000 Oct 29  2:00
			-5:00	-	EST	2000 Nov  5  0:00
			-6:00	-	CST	2001 Apr  1  3:00
			-7:00	Canada	M%sT
Zone America/Inuvik	0	-	-00	1953 # Inuvik founded
			-8:00	NT_YK	P%sT	1979 Apr lastSun  2:00
			-7:00	NT_YK	M%sT	1980
			-7:00	Canada	M%sT
Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
			-9:00	NT_YK	Y%sT	1965
			-9:00	Yukon	Y%sT	1966 Feb 27  0:00
			-8:00	-	PST	1980
			-8:00	Canada	P%sT	2020 Nov  1
			-7:00	-	MST
Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
			-9:00	NT_YK	Y%sT	1965
			-9:00	Yukon	Y%sT	1973 Oct 28  0:00
			-8:00	-	PST	1980
			-8:00	Canada	P%sT	2020 Nov  1
			-7:00	-	MST


###############################################################################

# Mexico

# From Paul Eggert (2014-12-07):
# The Investigation and Analysis Service of the
# Mexican Library of Congress (MLoC) has published a
# history of Mexican local time (in Spanish)
# http://www.diputados.gob.mx/bibliot/publica/inveyana/polisoc/horver/index.htm
#
# Here are the discrepancies between Shanks & Pottenger (S&P) and the MLoC.
# (In all cases we go with the MLoC.)
# S&P report that Baja was at -8:00 in 1922/1923.
# S&P say the 1930 transition in Baja was 1930-11-16.
# S&P report no DST during summer 1931.
# S&P report a transition at 1932-03-30 23:00, not 1932-04-01.

# From Gwillim Law (2001-02-20):
# There are some other discrepancies between the Decrees page and the
# tz database.  I think they can best be explained by supposing that
# the researchers who prepared the Decrees page failed to find some of
# the relevant documents.

# From Heitor David Pinto (2024-08-04):
# In 1931, the decree implementing DST specified that it would take
# effect on 30 April....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?cod_diario=192270&pagina=2&seccion=1
#
# In 1981, the decree changing Campeche, Yucatán and Quintana Roo to UTC-5
# specified that it would enter into force on 26 December 1981 at 2:00....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4705667&fecha=23/12/1981&cod_diario=202796
#
# In 1982, the decree returning Campeche and Yucatán to UTC-6 specified that
# it would enter into force on 2 November 1982 at 2:00....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?cod_diario=205689&pagina=3&seccion=0
#
# Quintana Roo changed to UTC-6 on 4 January 1983 at 0:00, and again
# to UTC-5 on 26 October 1997 at 2:00....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4787355&fecha=28/12/1982&cod_diario=206112
# https://www.dof.gob.mx/nota_to_imagen_fs.php?cod_diario=209559&pagina=15&seccion=0
#
# Durango, Coahuila, Nuevo León and Tamaulipas were set to UTC-7 on 1 January
# 1922, and changed to UTC-6 on 10 June 1927.  Then Durango, Coahuila and
# Nuevo León (but not Tamaulipas) returned to UTC-7 on 15 November 1930,
# observed DST in 1931, and changed again to UTC-6 on 1 April 1932....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4441846&fecha=29/12/1921&cod_diario=187468
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4541520&fecha=09/06/1927&cod_diario=193920
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4491963&fecha=15/11/1930&cod_diario=190835
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4418437&fecha=21/01/1932&cod_diario=185588
#
# ... the ... 10 June 1927 ... decree only said 10 June 1927, without
# specifying a time, so I suppose that it should be considered at 0:00.
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4541520&fecha=09/06/1927&cod_diario=193920
#
# In 1942, the decree changing Baja California, Baja California Sur, Sonora,
# Sinaloa and Nayarit to UTC-7 was published on 24 April, but it said that it
# would apply from 1 April, so it's unclear when the change actually
# occurred. The database currently shows 24 April 1942.
# https://www.dof.gob.mx/nota_to_imagen_fs.php?cod_diario=192203&pagina=2&seccion=1
#
# Baja California Sur, Sonora, Sinaloa and Nayarit never used UTC-8.  The ...
# 14 January 1949 ... change [to UTC-8] only occurred in Baja California.
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4515613&fecha=13/01/1949&cod_diario=192309
#
# In 1945, the decree changing Baja California to UTC-8 specified that it
# would take effect on the third day from its publication.
# It was published on 12 November, so it would take effect on 15 November....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4555049&fecha=12/11/1945&cod_diario=194763
#
# In 1948, the decree changing Baja California to UTC-7 specified that it
# would take effect on "this date".  The decree was made on 13 March,
# but published on 5 April, so it's unclear when the change actually occurred.
# The database currently shows 5 April 1948.
# https://www.dof.gob.mx/nota_to_imagen_fs.php?cod_diario=188624&pagina=2&seccion=0
#
# In 1949, the decree changing Baja California to UTC-8 was published on 13
# January, but it said that it would apply from 1 January, so it's unclear when
# the change actually occurred.  The database currently shows 14 January 1949.
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4515613&fecha=13/01/1949&cod_diario=192309
#
# Baja California also observed UTC-7 from 1 May to 24 September 1950,
# from 29 April to 30 September 1951 at 2:00,
# and from 27 April to 28 September 1952 at 2:00....
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4600403&fecha=29/04/1950&cod_diario=197505
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4623553&fecha=23/09/1950&cod_diario=198805
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4469444&fecha=27/04/1951&cod_diario=189317
# https://www.dof.gob.mx/nota_to_imagen_fs.php?codnota=4533868&fecha=10/03/1952&cod_diario=193465
#
# All changes in Baja California from 1948 to 1952 match those in California,
# on the same dates or with a difference of one day.
# So it may be easier to implement these changes as DST with rule CA
# during this whole period.

# From Alois Treindl (2025-07-29):
# I did a quick newspaper archive research on https://hndm.iib.unam.mx/
# and found that Periódico Oficial del Estado de Baja California Norte
# (1973-04-20) states clearly that DST was observed from last Sunday
# in April to last Sunday in October....  I have a few more data from the
# official bulletin for DST begin or end in Baja California 1964 1967 1969
# 1972 1973 (already sent) 1974 1975 1976 I do not know whether it is safe to
# assume that it also applied in the years where I did not yet find proof.
# The 1974 end of DST contains a reference to an Acuerdo of 1973-dec-20 which
# I could not find....  One might assume that Baja California, which followed
# US-CA in all these other yours, did the same.
#
# From Paul Eggert (2025-08-04):
# Assume that Tijuana agreed with San Diego from 1953 through 1996,
# as this agrees with Alois Treindl's data and with Shanks.
# For now, keep the slightly-different 1948/1952 history for Baja California,
# as we have no information on whether 1948/1952 clocks in Tijuana followed
# the decrees or followed San Diego.

# From Mark Schapiro, writing in The Nation (2002-10-28):
# https://www.thenation.com/article/archive/sowing-disaster/
# When Mexican clocks were turned back for daylight saving time in the spring,
# the Zapotecs refused to make the adjustment, insisting that they live in
# "God's time," not in what they derisively call "Fox time," referring to
# President Vicente Fox in far-off Mexico City.
# From Paul Eggert (2025-08-04):
# Unfortunately we have no data to track this informal practice.

# From Alan Perry (1996-02-15):
# A guy from our Mexico subsidiary finally found the Presidential Decree
# outlining the timezone changes in Mexico.
#
# ------------- Begin Forwarded Message -------------
#
# I finally got my hands on the Official Presidential Decree that sets up the
# rules for the DST changes. The rules are:
#
# 1. The country is divided in 3 timezones:
#    - Baja California Norte (the Mexico/BajaNorte TZ)
#    - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
#    - The rest of the country (the Mexico/General TZ)
#
# 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
#    at 2:00 AM, the times in each zone are as follows:
#    BajaNorte: GMT+7
#    BajaSur:   GMT+6
#    General:   GMT+5
#
# 3. The rest of the year, the times are as follows:
#    BajaNorte: GMT+8
#    BajaSur:   GMT+7
#    General:   GMT+6
#
# The Decree was published in Mexico's Official Newspaper on January 4th.
#
# -------------- End Forwarded Message --------------
# From Paul Eggert (1996-06-12):
# For an English translation of the decree, see
# "Diario Oficial: Time Zone Changeover" (1996-01-04).
# http://mexico-travel.com/extra/timezone_eng.html

# From Rives McDow (1998-10-08):
# The State of Quintana Roo has reverted back to central STD and DST times
# (i.e. UTC -0600 and -0500 as of 1998-08-02).

# From Rives McDow (2000-01-10):
# Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
# zone 5 hours from the International Date Line, and will not observe daylight
# savings time so as to stay on the same time zone as the southern part of
# Arizona year round.

# From Jesper Nørgaard, translating
# <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
# In Oaxaca, the 55.000 teachers from the Section 22 of the National
# Syndicate of Education Workers, refuse to apply daylight saving each
# year, so that the more than 10,000 schools work at normal hour the
# whole year.

# From Gwillim Law (2001-01-19):
# <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
# (translated):...
# January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
# that Summer Time will be reduced from seven to five months, starting
# this year....
# http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001
# [translated], says "summer time will ... take effect on the first Sunday
# in May, and end on the last Sunday of September.

# From Arthur David Olson (2001-01-25):
# The 2001-01-24 traditional Washington Post contained the page one
# story "Timely Issue Divides Mexicans."...
# http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
# ... Mexico City Mayor López Obrador "...is threatening to keep
# Mexico City and its 20 million residents on a different time than
# the rest of the country..." In particular, López Obrador would abolish
# observation of Daylight Saving Time.

# Official statute published by the Energy Department
# http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre
# (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
# and Sonora with no DST.  This was reported by Jesper Nørgaard (2001-02-03).

# From Paul Eggert (2001-03-03):
#
# https://www.latimes.com/archives/la-xpm-2001-mar-03-mn-32561-story.html
# James F. Smith writes in today's LA Times
# * Sonora will continue to observe standard time.
# * Last week Mexico City's mayor Andrés Manuel López Obrador decreed that
#   the Federal District will not adopt DST.
# * 4 of 16 district leaders announced they'll ignore the decree.
# * The decree does not affect federal-controlled facilities including
#   the airport, banks, hospitals, and schools.
#
# For now we'll assume that the Federal District will bow to federal rules.

# From Jesper Nørgaard (2001-04-01):
# I found some references to the Mexican application of daylight
# saving, which modifies what I had already sent you, stating earlier
# that a number of northern Mexican states would go on daylight
# saving. The modification reverts this to only cover Baja California
# (Norte), while all other states (except Sonora, who has no daylight
# saving all year) will follow the original decree of president
# Vicente Fox, starting daylight saving May 6, 2001 and ending
# September 30, 2001.
# References: "Diario de Monterrey" <http://www.diariodemonterrey.com/index.asp>
# Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)

# From Reuters (2001-09-04):
# Mexico's Supreme Court on Tuesday declared that daylight savings was
# unconstitutional in Mexico City, creating the possibility the
# capital will be in a different time zone from the rest of the nation
# next year....  The Supreme Court's ruling takes effect at 2:00
# a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
# standard time. "This is so residents of the Federal District are not
# subject to unexpected time changes," a statement from the court said.

# From Jesper Nørgaard Welen (2002-03-12):
# ... consulting my local grocery store(!) and my coworkers, they all insisted
# that a new decision had been made to reinstate US style DST in Mexico....
# http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
# confirms this.  Sonora as usual is the only state where DST is not applied.

# From Steffen Thorsen (2009-12-28):
#
# Steffen Thorsen wrote:
# > Mexico's House of Representatives has approved a proposal for northern
# > Mexico's border cities to share the same daylight saving schedule as
# > the United States.
# Now this has passed both the Congress and the Senate, so starting from
# 2010, some border regions will be the same:
# http://www.signonsandiego.com/news/2009/dec/28/clocks-will-match-both-sides-border/
# http://www.elmananarey.com/diario/noticia/nacional/noticias/empatan_horario_de_frontera_con_eu/621939
# (Spanish)
#
# Could not find the new law text, but the proposed law text changes are here:
# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/20091210-V.pdf
# (Gaceta Parlamentaria)
#
# There is also a list of the votes here:
# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
#
# Our page:
# https://www.timeanddate.com/news/time/north-mexico-dst-change.html

# From Arthur David Olson (2010-01-20):
# The page
# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
# includes this text:
# En los municipios fronterizos de Tijuana y Mexicali en Baja California;
# Juárez y Ojinaga en Chihuahua; Acuña y Piedras Negras en Coahuila;
# Anáhuac en Nuevo León; y Nuevo Laredo, Reynosa y Matamoros en
# Tamaulipas, la aplicación de este horario estacional surtirá efecto
# desde las dos horas del segundo domingo de marzo y concluirá a las dos
# horas del primer domingo de noviembre.
# En los municipios fronterizos que se encuentren ubicados en la franja
# fronteriza norte en el territorio comprendido entre la línea
# internacional y la línea paralela ubicada a una distancia de veinte
# kilómetros, así como la Ciudad de Ensenada, Baja California, hacia el
# interior del país, la aplicación de este horario estacional surtirá
# efecto desde las dos horas del segundo domingo de marzo y concluirá a
# las dos horas del primer domingo de noviembre.

# From Steffen Thorsen (2014-12-08), translated by Gwillim Law:
# The Mexican state of Quintana Roo will likely change to EST in 2015.
#
# http://www.unioncancun.mx/articulo/2014/12/04/medio-ambiente/congreso-aprueba-una-hora-mas-de-sol-en-qroo
# "With this change, the time conflict that has existed between the municipios
# of Quintana Roo and the municipio of Felipe Carrillo Puerto may come to an
# end. The latter declared itself in rebellion 15 years ago when a time change
# was initiated in Mexico, and since then it has refused to change its time
# zone along with the rest of the country."
#
# From Steffen Thorsen (2015-01-14), translated by Gwillim Law:
# http://sipse.com/novedades/confirman-aplicacion-de-nueva-zona-horaria-para-quintana-roo-132331.html
# "...the new time zone will come into effect at two o'clock on the first Sunday
# of February, when we will have to advance the clock one hour from its current
# time..."
# Also, the new zone will not use DST.
#
# From Carlos Raúl Perasso (2015-02-02):
# The decree that modifies the Mexican Hour System Law has finally
# been published at the Diario Oficial de la Federación
# http://www.dof.gob.mx/nota_detalle.php?codigo=5380123&fecha=31/01/2015
# It establishes 5 zones for Mexico:
# 1- Zona Centro (Central Zone): Corresponds to longitude 90 W,
#    includes most of Mexico, excluding what's mentioned below.
# 2- Zona Pacífico (Pacific Zone): Longitude 105 W, includes the
#    states of Baja California Sur; Chihuahua; Nayarit (excluding Bahía
#    de Banderas which lies in Central Zone); Sinaloa and Sonora.
# 3- Zona Noroeste (Northwest Zone): Longitude 120 W, includes the
#    state of Baja California.
# 4- Zona Sureste (Southeast Zone): Longitude 75 W, includes the state
#    of Quintana Roo.
# 5- The islands, reefs and keys shall take their timezone from the
#    longitude they are located at.

# From Paul Eggert (2022-10-28):
# The new Mexican law was published today:
# https://www.dof.gob.mx/nota_detalle.php?codigo=5670045&fecha=28/10/2022
# This abolishes DST except where US DST rules are observed,
# and in addition changes all of Chihuahua to -06 with no DST.

# From Heitor David Pinto (2022-11-28):
# Now the northern [municipios] want to have the same time zone as the
# respective neighboring cities in the US, for example Juárez in UTC-7 with
# DST, matching El Paso, and Ojinaga in UTC-6 with DST, matching Presidio....
# the president authorized the publication of the decree for November 29,
# so the time change would occur on November 30 at 0:00.
# http://puentelibre.mx/noticia/ciudad_juarez_cambio_horario_noviembre_2022/

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Mexico	1931	only	-	Apr	30	0:00	1:00	D
Rule	Mexico	1931	only	-	Oct	1	0:00	0	S
Rule	Mexico	1939	only	-	Feb	5	0:00	1:00	D
Rule	Mexico	1939	only	-	Jun	25	0:00	0	S
Rule	Mexico	1940	only	-	Dec	9	0:00	1:00	D
Rule	Mexico	1941	only	-	Apr	1	0:00	0	S
Rule	Mexico	1943	only	-	Dec	16	0:00	1:00	W # War
Rule	Mexico	1944	only	-	May	1	0:00	0	S
Rule	Mexico	1950	only	-	Feb	12	0:00	1:00	D
Rule	Mexico	1950	only	-	Jul	30	0:00	0	S
Rule	Mexico	1996	2000	-	Apr	Sun>=1	2:00	1:00	D
Rule	Mexico	1996	2000	-	Oct	lastSun	2:00	0	S
Rule	Mexico	2001	only	-	May	Sun>=1	2:00	1:00	D
Rule	Mexico	2001	only	-	Sep	lastSun	2:00	0	S
Rule	Mexico	2002	2022	-	Apr	Sun>=1	2:00	1:00	D
Rule	Mexico	2002	2022	-	Oct	lastSun	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
# Quintana Roo; represented by Cancún
Zone America/Cancun	-5:47:04 -	LMT	1922 Jan  1  6:00u
			-6:00	-	CST	1981 Dec 26  2:00
			-5:00	-	EST	1983 Jan  4  0:00
			-6:00	Mexico	C%sT	1997 Oct 26  2:00
			-5:00	Mexico	E%sT	1998 Aug  2  2:00
			-6:00	Mexico	C%sT	2015 Feb  1  2:00
			-5:00	-	EST
# Campeche, Yucatán; represented by Mérida
Zone America/Merida	-5:58:28 -	LMT	1922 Jan  1  6:00u
			-6:00	-	CST	1981 Dec 26  2:00
			-5:00	-	EST	1982 Nov  2  2:00
			-6:00	Mexico	C%sT
# Coahuila, Nuevo León, Tamaulipas (near US border)
# This includes the following municipios:
#   in Coahuila: Acuña, Allende, Guerrero, Hidalgo, Jiménez, Morelos, Nava,
#     Ocampo, Piedras Negras, Villa Unión, Zaragoza
#   in Nuevo León: Anáhuac
#   in Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo,
#     Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros.
# https://www.dof.gob.mx/nota_detalle.php?codigo=5670045&fecha=28/10/2022
Zone America/Matamoros	-6:30:00 -	LMT	1922 Jan  1  6:00u
			-6:00	-	CST	1988
			-6:00	US	C%sT	1989
			-6:00	Mexico	C%sT	2010
			-6:00	US	C%sT
# Durango; Coahuila, Nuevo León, Tamaulipas (away from US border)
Zone America/Monterrey	-6:41:16 -	LMT	1922 Jan  1  6:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1988
			-6:00	US	C%sT	1989
			-6:00	Mexico	C%sT
# Central Mexico
Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	Mexico	C%sT	2001 Sep 30  2:00
			-6:00	-	CST	2002 Feb 20
			-6:00	Mexico	C%sT
# Chihuahua (near US border - western side)
# This includes the municipios of Janos, Ascensión, Juárez, Guadalupe, and
# Práxedis G Guerrero.
# https://gaceta.diputados.gob.mx/PDF/65/2022/nov/20221124-VII.pdf
Zone America/Ciudad_Juarez -7:05:56 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1996
			-6:00	Mexico	C%sT	1998
			-6:00	-	CST	1998 Apr Sun>=1  3:00
			-7:00	Mexico	M%sT	2010
			-7:00	US	M%sT	2022 Oct 30  2:00
			-6:00	-	CST	2022 Nov 30  0:00
			-7:00	US	M%sT
# Chihuahua (near US border - eastern side)
# This includes the municipios of Coyame del Sotol, Ojinaga, and Manuel
# Benavides.
# https://gaceta.diputados.gob.mx/PDF/65/2022/nov/20221124-VII.pdf
Zone America/Ojinaga	-6:57:40 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1996
			-6:00	Mexico	C%sT	1998
			-6:00	-	CST	1998 Apr Sun>=1  3:00
			-7:00	Mexico	M%sT	2010
			-7:00	US	M%sT	2022 Oct 30  2:00
			-6:00	-	CST	2022 Nov 30  0:00
			-6:00	US	C%sT
# Chihuahua (away from US border)
Zone America/Chihuahua	-7:04:20 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1996
			-6:00	Mexico	C%sT	1998
			-6:00	-	CST	1998 Apr Sun>=1  3:00
			-7:00	Mexico	M%sT	2022 Oct 30  2:00
			-6:00	-	CST
# Sonora
Zone America/Hermosillo	-7:23:52 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1942 Apr 24
			-7:00	-	MST	1996
			-7:00	Mexico	M%sT	1999
			-7:00	-	MST

# Baja California Sur, Nayarit (except Bahía de Banderas), Sinaloa
Zone America/Mazatlan	-7:05:40 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1942 Apr 24
			-7:00	-	MST	1970
			-7:00	Mexico	M%sT

# Bahía de Banderas

# From Alexander Krivenyshev (2010-04-21):
# According to news, Bahía de Banderas (Mexican state of Nayarit)
# changed time zone UTC-7 to new time zone UTC-6 on April 4, 2010 (to
# share the same time zone as nearby city Puerto Vallarta, Jalisco).
#
# (Spanish)
# Bahía de Banderas homologa su horario al del centro del
# país, a partir de este domingo
# http://www.nayarit.gob.mx/notes.asp?id=20748
#
# Bahía de Banderas homologa su horario con el del Centro del
# País
# http://www.bahiadebanderas.gob.mx/principal/index.php?option=com_content&view=article&id=261:bahia-de-banderas-homologa-su-horario-con-el-del-centro-del-pais&catid=42:comunicacion-social&Itemid=50
#
# (English)
# Puerto Vallarta and Bahía de Banderas: One Time Zone
# http://virtualvallarta.com/puertovallarta/puertovallarta/localnews/2009-12-03-Puerto-Vallarta-and-Bahia-de-Banderas-One-Time-Zone.shtml
# http://www.worldtimezone.com/dst_news/dst_news_mexico08.html
#
# "Mexico's Senate approved the amendments to the Mexican Schedule System that
# will allow Bahía de Banderas and Puerto Vallarta to share the same time
# zone ..."
# Baja California Sur, Nayarit, Sinaloa

# From Arthur David Olson (2010-05-01):
# Use "Bahia_Banderas" to keep the name to fourteen characters.

Zone America/Bahia_Banderas -7:01:00 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1927 Jun 10
			-6:00	-	CST	1930 Nov 15
			-7:00	Mexico	M%sT	1932 Apr  1
			-6:00	-	CST	1942 Apr 24
			-7:00	-	MST	1970
			-7:00	Mexico	M%sT	2010 Apr  4  2:00
			-6:00	Mexico	C%sT

# Baja California
Zone America/Tijuana	-7:48:04 -	LMT	1922 Jan  1  7:00u
			-7:00	-	MST	1924
			-8:00	-	PST	1927 Jun 10
			-7:00	-	MST	1930 Nov 15
			-8:00	-	PST	1931 Apr  1
			-8:00	1:00	PDT	1931 Sep 30
			-8:00	-	PST	1942 Apr 24
			-8:00	1:00	PWT	1945 Aug 14 23:00u
			-8:00	1:00	PPT	1945 Nov 15 # Peace
			-8:00	-	PST	1948 Apr  5
			-8:00	1:00	PDT	1949 Jan 14
			-8:00	-	PST	1950 May  1
			-8:00	1:00	PDT	1950 Sep 24
			-8:00	-	PST	1951 Apr 29  2:00
			-8:00	1:00	PDT	1951 Sep 30  2:00
			-8:00	-	PST	1952 Apr 27  2:00
			-8:00	1:00	PDT	1952 Sep 28  2:00
			-8:00	CA	P%sT	1967
			-8:00	US	P%sT	1996
			-8:00	Mexico	P%sT	2001
			-8:00	US	P%sT	2002 Feb 20
			-8:00	Mexico	P%sT	2010
			-8:00	US	P%sT
# From Paul Eggert (2006-03-22):
# Formerly there was an America/Ensenada zone, which differed from
# America/Tijuana only in that it did not observe DST from 1976
# through 1995.  This was as per Shanks (1999).  But Shanks & Pottenger say
# Ensenada did not observe DST from 1948 through 1975.  Guy Harris reports
# that the 1987 OAG says "Only Ensenada, Mexicali, San Felipe and
# Tijuana observe DST," which agrees with Shanks & Pottenger but implies that
# DST-observance was a town-by-town matter back then.  This concerns
# data after 1970 so most likely there should be at least one Zone
# other than America/Tijuana for Baja, but it's not clear yet what its
# name or contents should be.
#
# From Paul Eggert (2015-10-08):
# Formerly there was an America/Santa_Isabel zone, but this appears to
# have come from a misreading of
# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
# It has been moved to the 'backward' file.
#
# From Paul Eggert (2022-10-28):
# Today's new law states that the entire state of Baja California
# follows US DST rules, which agrees with simplifications noted above.
#
#
# Revillagigedo Is
# no information

###############################################################################

# Barbados

# For 1899 Milne gives -3:58:29.2.

# From P Chan (2020-12-09 and 2020-12-11):
# Standard time of GMT-4 was adopted in 1911.
# Definition of Time Act, 1911 (1911-7) [1911-08-28]
# 1912, Laws of Barbados (5 v.), OCLC Number: 919801291, Vol. 4, Image No. 522
# 1944, Laws of Barbados (5 v.), OCLC Number: 84548697, Vol. 4, Image No. 122
# http://llmc.com/browse.aspx?type=2&coll=85&div=297
#
# DST was observed in 1942-44.
# Defence (Daylight Saving) Regulations, 1942, 1942-04-13
# Defence (Daylight Saving) (Repeal) Regulations, 1942, 1942-08-22
# Defence (Daylight Saving) Regulations, 1943, 1943-04-16
# Defence (Daylight Saving) (Repeal) Regulations, 1943, 1943-09-01
# Defence (Daylight Saving) Regulations, 1944, 1944-03-21
# [Defence (Daylight Saving) (Amendment) Regulations 1944, 1944-03-28]
# Defence (Daylight Saving) (Repeal) Regulations, 1944, 1944-08-30
#
# 1914-, Subsidiary Legis., Annual Vols. OCLC Number: 226290591
# 1942: Image Nos. 527-528, 555-556
# 1943: Image Nos. 178-179, 198
# 1944: Image Nos. 113-115, 129
# http://llmc.com/titledescfull.aspx?type=2&coll=85&div=297&set=98437
#
# From Tim Parenti (2021-02-20):
# The transitions below are derived from P Chan's sources, except that the 1977
# through 1980 transitions are from Shanks & Pottenger since we have no better
# data there.  Of particular note, the 1944 DST regulation only advanced the
# time to "exactly three and a half hours later than Greenwich mean time", as
# opposed to "three hours" in the 1942 and 1943 regulations.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Barb	1942	only	-	Apr	19	5:00u	1:00	D
Rule	Barb	1942	only	-	Aug	31	6:00u	0	S
Rule	Barb	1943	only	-	May	 2	5:00u	1:00	D
Rule	Barb	1943	only	-	Sep	 5	6:00u	0	S
Rule	Barb	1944	only	-	Apr	10	5:00u	0:30	-
Rule	Barb	1944	only	-	Sep	10	6:00u	0	S
Rule	Barb	1977	only	-	Jun	12	2:00	1:00	D
Rule	Barb	1977	1978	-	Oct	Sun>=1	2:00	0	S
Rule	Barb	1978	1980	-	Apr	Sun>=15	2:00	1:00	D
Rule	Barb	1979	only	-	Sep	30	2:00	0	S
Rule	Barb	1980	only	-	Sep	25	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
		#STDOFF	-3:58:29.2
Zone America/Barbados	-3:58:29 -	LMT	1911 Aug 28 # Bridgetown
			-4:00	Barb	A%sT	1944
			-4:00	Barb	AST/-0330 1945
			-4:00	Barb	A%sT

# Belize

# From P Chan (2020-11-03):
# Below are some laws related to the time in British Honduras/Belize:
#
# Definition of Time Ordinance, 1927 (No.4 of 1927) [1927-04-01]
# Ordinances of British Honduras Passed in the Year 1927, p 19-20
# https://books.google.com/books?id=LqEpAQAAMAAJ&pg=RA3-PA19
#
# Definition of Time (Amendment) Ordinance, 1942 (No. 5 of 1942) [1942-06-27]
# Ordinances of British Honduras Passed in the Year 1942, p 31-32
# https://books.google.com/books?id=h6MpAQAAMAAJ&pg=RA6-PA95-IA44
#
# Definition of Time Ordinance, 1945 (No. 19 of 1945) [1945-12-15]
# Ordinances of British Honduras Passed in the Year 1945, p 49-50
# https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA2-PP1
#
# Definition of Time Ordinance, 1947 (No. 1 of 1947) [1947-03-11]
# Ordinances of British Honduras Passed in the Year 1947, p 1-2
# https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA3-PA1
#
# Time (Definition of) Ordinance  (Chapter 180)
# The Laws of British Honduras in Force on the 15th Day of September, 1958 , Volume IV, p 2580
# https://books.google.com/books?id=v5QpAQAAMAAJ&pg=PA2580
#
# Time (Definition of) (Amendment) Ordinance, 1968 (No. 13 of 1968) [1968-08-03]
# https://books.google.com/books?id=xij7KEB_58wC&pg=RA1-PA428-IA9
#
# Definition of Time Act (Chapter 339)
# Law of Belize, Revised Edition 2000
# http://www.belizelaw.org/web/lawadmin/PDF%20files/cap339.pdf

# From Paul Eggert (2020-11-03):
# The transitions below are derived from P Chan's sources, except that the
# 1973 through 1983 transitions are from Shanks & Pottenger since we have
# no better data there.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Belize	1918	1941	-	Oct	Sat>=1	24:00	0:30	-0530
Rule	Belize	1919	1942	-	Feb	Sat>=8	24:00	0	CST
Rule	Belize	1942	only	-	Jun	27	24:00	1:00	CWT
Rule	Belize	1945	only	-	Aug	14	23:00u	1:00	CPT
Rule	Belize	1945	only	-	Dec	15	24:00	0	CST
Rule	Belize	1947	1967	-	Oct	Sat>=1	24:00	0:30	-0530
Rule	Belize	1948	1968	-	Feb	Sat>=8	24:00	0	CST
Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	CDT
Rule	Belize	1974	only	-	Feb	 9	0:00	0	CST
Rule	Belize	1982	only	-	Dec	18	0:00	1:00	CDT
Rule	Belize	1983	only	-	Feb	12	0:00	0	CST
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone	America/Belize	-5:52:48 -	LMT	1912 Apr  1
			-6:00	Belize	%s

# Bermuda

# From Paul Eggert (2022-07-27):
# For 1899 Milne gives -4:19:18.3 as the meridian of the clock tower,
# Bermuda dockyard, Ireland I.  This agrees with standard offset given in the
# Daylight Saving Act, 1917 cited below.
# It is not known when this time became standard for Bermuda; guess 1890.
# The transition to -04 was specified by:
# 1930: The Time Zone Act, 1929 (1929: No. 39) [1929-11-08]
# https://books.google.com/books?id=7tdMAQAAIAAJ&pg=RA54-PP1

# From P Chan (2020-11-20):
# Most of the information can be found online from the Bermuda National
# Library - Digital Collection which includes The Royal Gazette (RG) until 1957
# https://bnl.contentdm.oclc.org/digital/
# I will cite the ID.  For example, [10000] means
# https://bnl.contentdm.oclc.org/digital/collection/BermudaNP02/id/10000
#
# 1917: Apr 5 midnight to Sep 30 midnight
# Daylight Saving Act, 1917 (1917 No. 13) [1917-04-02]
# Bermuda Acts and Resolves 1917, p 37-38
# https://books.google.com/books?id=M-lCAQAAMAAJ&pg=PA36-IA2
# RG, 1917-04-04, p 6 [42340] gives the spring forward date.
#
# 1918: Apr 13 midnight to Sep 15 midnight
# Daylight Saving Act, 1918 (1918 No. 9) [1918-04-06]
# Bermuda Acts and Resolves 1917, p 13
# https://books.google.com/books?id=K-lCAQAAMAAJ&pg=RA1-PA7
#
# Note that local mean time was still used before 1930.
#
# During WWII, DST was introduced by Defence Regulations
# 1942: Jan 11 02:00 to Oct 18 02:00 [113646], [115726]
# 1943: Mar 21 02:00 to Oct 31 02:00 [116704], [118193]
# 1944: Mar 12 02:00 to Nov 5 02:00 [119225], [121593]
# 1945: Mar 11 02:00 to Nov 4 02:00 [122369], [124461]
# RG, 1942-01-08, p 2, 1942-10-12, p 2 , 1943-03-06, p 2, 1943-09-03, p 1,
# 1944-02-29, p 6, 1944-09-20, p 2, 1945-02-13, p 2, 1945-11-03, p 1
#
# In 1946, the House of Assembly rejected DST twice. [128686], [128076]
# RG, 1946-03-16 p 1,1946-04-13 p 1
#
# 1947: third Sunday in May 02:00 to second Sunday in September 02:00
# DST in 1947 was defined in the Daylight Saving Act, 1947 (1947: No. 12)
# which expired at the end of the year.  [125784] ,[132405], [144454], [138226]
# RG, 1947-02-27, p 1, 1947-05-15, p 1, 1947-09-13, p 1, 1947-12-30, p 1
#
# 1948-1952: fourth Sunday in May 02:00 to first Sunday in September 02:00
# DST in 1948 was defined in the Daylight Saving Act, 1948 (1948 : No. 12)
# which was set to expired at the end of the year but it was extended until
# the end of 1952 and was not further extended.
# [129802], [139403], [146008], [135240], [144330], [139049], [143309],
# [148271], [149773], [153589], [153802], [155924]
# RG, 1948-04-13, p 1, 1948-05-22, p 1, 1948-09-04, p 1, 1949-05-21, p1,
# 1949-09-03, p 1, 1950-05-27 p 1, 1950-09-02, p 1, 1951-05-27, p 1,
# 1951-09-01, p 1, 1952-05-23, p 1, 1952-09-26, p 1, 1952-12-21, p 8
#
# In 1953-1955, the House of Assembly rejected DST each year. [158996],
# [162620], [166720] RG, 1953-05-02, p 1, 1954-04-01 p 1, 1955-03-12, p 1
#
# 1956: fourth Sunday in May 02:00 to last Sunday in October 02:00
# Time Zone (Seasonal Variation) Act, 1956 (1956: No.44) [1956-05-25]
# Bermuda Public Acts 1956, p 331-332
# https://books.google.com/books?id=Xs1AlmD_cEwC&pg=PA63
#
# The extension of the Act was rejected by the House of Assembly. [176218]
# RG, 1956-12-13, p 1
#
# From the Chronological Table of Public and Private Acts up to 1985, it seems
# that there does not exist other Acts related to DST before 1973.
# https://books.google.com/books?id=r9hMAQAAIAAJ&pg=RA23-PA1
# Public Acts of the Legislature of the Islands of Bermuda, Together with
# Statutory Instruments in Force Thereunder, Vol VII

# From Dan Jones, reporting in The Royal Gazette (2006-06-26):
# Next year, however, clocks in the US will go forward on the second Sunday
# in March, until the first Sunday in November.  And, after the Time Zone
# (Seasonal Variation) Bill 2006 was passed in the House of Assembly on
# Friday, the same thing will happen in Bermuda.
# http://www.theroyalgazette.com/apps/pbcs.dll/article?AID=/20060529/NEWS/105290135

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Bermuda	1917	only	-	Apr	 5	24:00	1:00	-
Rule	Bermuda	1917	only	-	Sep	30	24:00	0	-
Rule	Bermuda	1918	only	-	Apr	13	24:00	1:00	-
Rule	Bermuda	1918	only	-	Sep	15	24:00	0	S
Rule	Bermuda	1942	only	-	Jan	11	 2:00	1:00	D
Rule	Bermuda	1942	only	-	Oct	18	 2:00	0	S
Rule	Bermuda	1943	only	-	Mar	21	 2:00	1:00	D
Rule	Bermuda	1943	only	-	Oct	31	 2:00	0	S
Rule	Bermuda	1944	1945	-	Mar	Sun>=8	 2:00	1:00	D
Rule	Bermuda	1944	1945	-	Nov	Sun>=1	 2:00	0	S
Rule	Bermuda	1947	only	-	May	Sun>=15	 2:00	1:00	D
Rule	Bermuda	1947	only	-	Sep	Sun>=8	 2:00	0	S
Rule	Bermuda	1948	1952	-	May	Sun>=22	 2:00	1:00	D
Rule	Bermuda	1948	1952	-	Sep	Sun>=1	 2:00	0	S
Rule	Bermuda	1956	only	-	May	Sun>=22	 2:00	1:00	D
Rule	Bermuda	1956	only	-	Oct	lastSun	 2:00	0	S

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
		#STDOFF	-4:19:18.3
Zone Atlantic/Bermuda	-4:19:18 -	LMT	1890	# Hamilton
			-4:19:18 Bermuda BMT/BST 1930 Jan 1  2:00
			-4:00	Bermuda	A%sT	1974 Apr 28  2:00
			-4:00	Canada	A%sT	1976
			-4:00	US	A%sT

# Costa Rica

# Milne gives -5:36:13.3 as San José mean time.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	CR	1979	1980	-	Feb	lastSun	0:00	1:00	D
Rule	CR	1979	1980	-	Jun	Sun>=1	0:00	0	S
Rule	CR	1991	1992	-	Jan	Sat>=15	0:00	1:00	D
# IATA SSIM (1991-09) says the following was at 1:00;
# go with Shanks & Pottenger.
Rule	CR	1991	only	-	Jul	 1	0:00	0	S
Rule	CR	1992	only	-	Mar	15	0:00	0	S
# There are too many San Josés elsewhere, so we'll use 'Costa Rica'.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
		#STDOFF	-5:36:13.3
Zone America/Costa_Rica	-5:36:13 -	LMT	1890        # San José
			-5:36:13 -	SJMT	1921 Jan 15 # San José Mean Time
			-6:00	CR	C%sT
# Coco
# no information; probably like America/Costa_Rica

# Cuba

# From Paul Eggert (2013-02-21):
# Milne gives -5:28:50.45 for the observatory at Havana, -5:29:23.57
# for the port, and -5:30 for meteorological observations.
# For now, stick with Shanks & Pottenger.

# From Arthur David Olson (1999-03-29):
# The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
# the Cuban National Team and the Baltimore Orioles was carried live on
# the Orioles Radio Network, including affiliate WTOP in Washington, DC.
# During the game, play-by-play announcer Jim Hunter noted that
# "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
# Time today."  (The "two hour" remark referred to losing one hour of
# sleep on 1999-03-28 - when the announcers were in Cuba as it switched
# to DST - and one more hour on 1999-04-04 - when the announcers will have
# returned to Baltimore, which switches on that date.)

# From Steffen Thorsen (2013-11-11):
# DST start in Cuba in 2004 ... does not follow the same rules as the
# years before.  The correct date should be Sunday 2004-03-28 00:00 ...
# https://web.archive.org/web/20040402060750/http://www.granma.cu/espanol/2004/marzo/sab27/reloj.html

# From Evert van der Veer via Steffen Thorsen (2004-10-28):
# Cuba is not going back to standard time this year.
# From Paul Eggert (2006-03-22):
# http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
# says that it's due to a problem at the Antonio Guiteras
# thermoelectric plant, and says "This October there will be no return
# to normal hours (after daylight saving time)".
# For now, let's assume that it's a temporary measure.

# From Carlos A. Carnero Delgado (2005-11-12):
# This year (just like in 2004-2005) there's no change in time zone
# adjustment in Cuba.  We will stay in daylight saving time:
# http://www.granma.cu/espanol/2005/noviembre/mier9/horario.html

# From Jesper Nørgaard Welen (2006-10-21):
# An article in GRANMA INTERNACIONAL claims that Cuba will end
# the 3 years of permanent DST next weekend, see
# http://www.granma.cu/ingles/2006/octubre/lun16/43horario.html
# "On Saturday night, October 28 going into Sunday, October 29, at 01:00,
# watches should be set back one hour - going back to 00:00 hours - returning
# to the normal schedule....

# From Paul Eggert (2007-03-02):
# <http://www.granma.cubaweb.cu/english/news/art89.html>, dated yesterday,
# says Cuban clocks will advance at midnight on March 10.
# For lack of better information, assume Cuba will use US rules,
# except that it switches at midnight standard time as usual.
#
# From Steffen Thorsen (2007-10-25):
# Carlos Alberto Fonseca Arauz informed me that Cuba will end DST one week
# earlier - on the last Sunday of October, just like in 2006.
#
# He supplied these references:
#
# http://www.prensalatina.com.mx/article.asp?ID={4CC32C1B-A9F7-42FB-8A07-8631AFC923AF}&language=ES
# http://actualidad.terra.es/sociedad/articulo/cuba_llama_ahorrar_energia_cambio_1957044.htm
#
# From Alex Krivenyshev (2007-10-25):
# Here is also article from Granma (Cuba):
#
# Regirá el Horario Normal desde el próximo domingo 28 de octubre
# http://www.granma.cubaweb.cu/2007/10/24/nacional/artic07.html
#
# http://www.worldtimezone.com/dst_news/dst_news_cuba03.html

# From Arthur David Olson (2008-03-09):
# I'm in Maryland which is now observing United States Eastern Daylight
# Time. At 9:44 local time I used RealPlayer to listen to
# http://media.enet.cu/radioreloj
# a Cuban information station, and heard
# the time announced as "ocho cuarenta y cuatro" ("eight forty-four"),
# indicating that Cuba is still on standard time.

# From Steffen Thorsen (2008-03-12):
# It seems that Cuba will start DST on Sunday, 2007-03-16...
# It was announced yesterday, according to this source (in Spanish):
# http://www.nnc.cubaweb.cu/marzo-2008/cien-1-11-3-08.htm
#
# Some more background information is posted here:
# https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
#
# The article also says that Cuba has been observing DST since 1963,
# while Shanks (and tzdata) has 1965 as the first date (except in the
# 1940's). Many other web pages in Cuba also claim that it has been
# observed since 1963, but with the exception of 1970 - an exception
# which is not present in tzdata/Shanks. So there is a chance we need to
# change some historic records as well.
#
# One example:
# http://www.radiohc.cu/espanol/noticias/mar07/11mar/hor.htm

# From Jesper Nørgaard Welen (2008-03-13):
# The Cuban time change has just been confirmed on the most authoritative
# web site, the Granma.  Please check out
# http://www.granma.cubaweb.cu/2008/03/13/nacional/artic10.html
#
# Basically as expected after Steffen Thorsen's information, the change
# will take place midnight between Saturday and Sunday.

# From Arthur David Olson (2008-03-12):
# Assume Sun>=15 (third Sunday) going forward.

# From Alexander Krivenyshev (2009-03-04)
# According to the Radio Reloj - Cuba will start Daylight Saving Time on
# midnight between Saturday, March 07, 2009 and Sunday, March 08, 2009-
# not on midnight March 14 / March 15 as previously thought.
#
# http://www.worldtimezone.com/dst_news/dst_news_cuba05.html
# (in Spanish)

# From Arthur David Olson (2009-03-09)
# I listened over the Internet to
# http://media.enet.cu/readioreloj
# this morning; when it was 10:05 a. m. here in Bethesda, Maryland the
# the time was announced as "diez cinco" - the same time as here, indicating
# that has indeed switched to DST. Assume second Sunday from 2009 forward.

# From Steffen Thorsen (2011-03-08):
# Granma announced that Cuba is going to start DST on 2011-03-20 00:00:00
# this year. Nothing about the end date known so far (if that has
# changed at all).
#
# Source:
# http://granma.co.cu/2011/03/08/nacional/artic01.html
#
# Our info:
# https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
#
# From Steffen Thorsen (2011-10-30)
# Cuba will end DST two weeks later this year. Instead of going back
# tonight, it has been delayed to 2011-11-13 at 01:00.
#
# One source (Spanish)
# http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
#
# Our page:
# https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
#
# From Steffen Thorsen (2012-03-01)
# According to Radio Reloj, Cuba will start DST on Midnight between March
# 31 and April 1.
#
# Radio Reloj has the following info (Spanish):
# http://www.radioreloj.cu/index.php/noticias-radio-reloj/71-miscelaneas/7529-cuba-aplicara-el-horario-de-verano-desde-el-1-de-abril
#
# Our info on it:
# https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html

# From Steffen Thorsen (2012-11-03):
# Radio Reloj and many other sources report that Cuba is changing back
# to standard time on 2012-11-04:
# http://www.radioreloj.cu/index.php/noticias-radio-reloj/36-nacionales/9961-regira-horario-normal-en-cuba-desde-el-domingo-cuatro-de-noviembre
# From Paul Eggert (2012-11-03):
# For now, assume the future rule is first Sunday in November.

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Cuba	1928	only	-	Jun	10	0:00	1:00	D
Rule	Cuba	1928	only	-	Oct	10	0:00	0	S
Rule	Cuba	1940	1942	-	Jun	Sun>=1	0:00	1:00	D
Rule	Cuba	1940	1942	-	Sep	Sun>=1	0:00	0	S
Rule	Cuba	1945	1946	-	Jun	Sun>=1	0:00	1:00	D
Rule	Cuba	1945	1946	-	Sep	Sun>=1	0:00	0	S
Rule	Cuba	1965	only	-	Jun	1	0:00	1:00	D
Rule	Cuba	1965	only	-	Sep	30	0:00	0	S
Rule	Cuba	1966	only	-	May	29	0:00	1:00	D
Rule	Cuba	1966	only	-	Oct	2	0:00	0	S
Rule	Cuba	1967	only	-	Apr	8	0:00	1:00	D
Rule	Cuba	1967	1968	-	Sep	Sun>=8	0:00	0	S
Rule	Cuba	1968	only	-	Apr	14	0:00	1:00	D
Rule	Cuba	1969	1977	-	Apr	lastSun	0:00	1:00	D
Rule	Cuba	1969	1971	-	Oct	lastSun	0:00	0	S
Rule	Cuba	1972	1974	-	Oct	8	0:00	0	S
Rule	Cuba	1975	1977	-	Oct	lastSun	0:00	0	S
Rule	Cuba	1978	only	-	May	7	0:00	1:00	D
Rule	Cuba	1978	1990	-	Oct	Sun>=8	0:00	0	S
Rule	Cuba	1979	1980	-	Mar	Sun>=15	0:00	1:00	D
Rule	Cuba	1981	1985	-	May	Sun>=5	0:00	1:00	D
Rule	Cuba	1986	1989	-	Mar	Sun>=14	0:00	1:00	D
Rule	Cuba	1990	1997	-	Apr	Sun>=1	0:00	1:00	D
Rule	Cuba	1991	1995	-	Oct	Sun>=8	0:00s	0	S
Rule	Cuba	1996	only	-	Oct	 6	0:00s	0	S
Rule	Cuba	1997	only	-	Oct	12	0:00s	0	S
Rule	Cuba	1998	1999	-	Mar	lastSun	0:00s	1:00	D
Rule	Cuba	1998	2003	-	Oct	lastSun	0:00s	0	S
Rule	Cuba	2000	2003	-	Apr	Sun>=1	0:00s	1:00	D
Rule	Cuba	2004	only	-	Mar	lastSun	0:00s	1:00	D
Rule	Cuba	2006	2010	-	Oct	lastSun	0:00s	0	S
Rule	Cuba	2007	only	-	Mar	Sun>=8	0:00s	1:00	D
Rule	Cuba	2008	only	-	Mar	Sun>=15	0:00s	1:00	D
Rule	Cuba	2009	2010	-	Mar	Sun>=8	0:00s	1:00	D
Rule	Cuba	2011	only	-	Mar	Sun>=15	0:00s	1:00	D
Rule	Cuba	2011	only	-	Nov	13	0:00s	0	S
Rule	Cuba	2012	only	-	Apr	1	0:00s	1:00	D
Rule	Cuba	2012	max	-	Nov	Sun>=1	0:00s	0	S
Rule	Cuba	2013	max	-	Mar	Sun>=8	0:00s	1:00	D

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone	America/Havana	-5:29:28 -	LMT	1890
			-5:29:36 -	HMT	1925 Jul 19 12:00 # Havana MT
			-5:00	Cuba	C%sT

# Dominican Republic

# From Steffen Thorsen (2000-10-30):
# Enrique Morales reported to me that the Dominican Republic has changed the
# time zone to Eastern Standard Time as of Sunday 29 at 2 am....
# http://www.listin.com.do/antes/261000/republica/princi.html

# From Paul Eggert (2000-12-04):
# That URL (2000-10-26, in Spanish) says they planned to use US-style DST.

# From Rives McDow (2000-12-01):
# Dominican Republic changed its mind and presidential decree on Tuesday,
# November 28, 2000, with a new decree.  On Sunday, December 3 at 1:00 AM the
# Dominican Republic will be reverting to 8 hours from the International Date
# Line, and will not be using DST in the foreseeable future.  The reason they
# decided to use DST was to be in synch with Puerto Rico, who was also going
# to implement DST.  When Puerto Rico didn't implement DST, the president
# decided to revert.


# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	DR	1966	only	-	Oct	30	0:00	1:00	EDT
Rule	DR	1967	only	-	Feb	28	0:00	0	EST
Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	-0430
Rule	DR	1970	only	-	Feb	21	0:00	0	EST
Rule	DR	1971	only	-	Jan	20	0:00	0	EST
Rule	DR	1972	1974	-	Jan	21	0:00	0	EST
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Santo_Domingo -4:39:36 -	LMT	1890
			-4:40	-	SDMT	1933 Apr  1 12:00 # S. Dom. MT
			-5:00	DR	%s	1974 Oct 27
			-4:00	-	AST	2000 Oct 29  2:00
			-5:00	US	E%sT	2000 Dec  3  1:00
			-4:00	-	AST

# El Salvador

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Salv	1987	1988	-	May	Sun>=1	0:00	1:00	D
Rule	Salv	1987	1988	-	Sep	lastSun	0:00	0	S
# There are too many San Salvadors elsewhere, so use America/El_Salvador
# instead of America/San_Salvador.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/El_Salvador -5:56:48 -	LMT	1921 # San Salvador
			-6:00	Salv	C%sT

# Guatemala
#
# From Gwillim Law (2006-04-22), after a heads-up from Oscar van Vlijmen:
# Diario Co Latino, at
# <http://www.diariocolatino.com/internacionales/detalles.asp?NewsID=8079>,
# says in an article dated 2006-04-19 that the Guatemalan government had
# decided on that date to advance official time by 60 minutes, to lessen the
# impact of the elevated cost of oil....  Daylight saving time will last from
# 2006-04-29 24:00 (Guatemalan standard time) to 2006-09-30 (time unspecified).
# From Paul Eggert (2006-06-22):
# The Ministry of Energy and Mines, press release CP-15/2006
# (2006-04-19), says DST ends at 24:00.  See
# http://www.sieca.org.gt/Sitio_publico/Energeticos/Doc/Medidas/Cambio_Horario_Nac_190406.pdf

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Guat	1973	only	-	Nov	25	0:00	1:00	D
Rule	Guat	1974	only	-	Feb	24	0:00	0	S
Rule	Guat	1983	only	-	May	21	0:00	1:00	D
Rule	Guat	1983	only	-	Sep	22	0:00	0	S
Rule	Guat	1991	only	-	Mar	23	0:00	1:00	D
Rule	Guat	1991	only	-	Sep	 7	0:00	0	S
Rule	Guat	2006	only	-	Apr	30	0:00	1:00	D
Rule	Guat	2006	only	-	Oct	 1	0:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Guatemala	-6:02:04 -	LMT	1918 Oct 5
			-6:00	Guat	C%sT

# Haiti
# From Gwillim Law (2005-04-15):
# Risto O. Nykänen wrote me that Haiti is now on DST.
# I searched for confirmation, and I found a press release
# on the Web page of the Haitian Consulate in Chicago (2005-03-31),
# <http://www.haitianconsulate.org/time.doc>.  Translated from French, it says:
#
#  "The Prime Minister's Communication Office notifies the public in general
#   and the press in particular that, following a decision of the Interior
#   Ministry and the Territorial Collectivities [I suppose that means the
#   provinces], Haiti will move to Eastern Daylight Time in the night from next
#   Saturday the 2nd to Sunday the 3rd.
#
#  "Consequently, the Prime Minister's Communication Office wishes to inform
#   the population that the country's clocks will be set forward one hour
#   starting at midnight.  This provision will hold until the last Saturday in
#   October 2005.
#
#  "Port-au-Prince, March 31, 2005"
#
# From Steffen Thorsen (2006-04-04):
# I have been informed by users that Haiti observes DST this year like
# last year, so the current "only" rule for 2005 might be changed to a
# "max" rule or to last until 2006. (Who knows if they will observe DST
# next year or if they will extend their DST like US/Canada next year).
#
# I have found this article about it (in French):
# http://www.haitipressnetwork.com/news.cfm?articleID=7612
#
# The reason seems to be an energy crisis.

# From Stephen Colebourne (2007-02-22):
# Some IATA info: Haiti won't be having DST in 2007.

# From Steffen Thorsen (2012-03-11):
# According to several news sources, Haiti will observe DST this year,
# apparently using the same start and end date as USA/Canada.
# So this means they have already changed their time.
#
# http://www.alterpresse.org/spip.php?article12510
# http://radiovision2000haiti.net/home/?p=13253
#
# From Arthur David Olson (2012-03-11):
# The alterpresse.org source seems to show a US-style leap from 2:00 a.m. to
# 3:00 a.m. rather than the traditional Haitian jump at midnight.
# Assume a US-style fall back as well.

# From Steffen Thorsen (2013-03-10):
# It appears that Haiti is observing DST this year as well, same rules
# as US/Canada.  They did it last year as well, and it looks like they
# are going to observe DST every year now...
#
# http://radiovision2000haiti.net/public/haiti-avis-changement-dheure-dimanche/
# http://www.canalplushaiti.net/?p=6714

# From Steffen Thorsen (2016-03-12):
# Jean Antoine, editor of www.haiti-reference.com informed us that Haiti
# are not going on DST this year.  Several other resources confirm this: ...
# https://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
# https://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
# http://news.anmwe.com/haiti-lheure-nationale-ne-sera-ni-avancee-ni-reculee-cette-annee/

# From Steffen Thorsen (2017-03-12):
# We have received 4 mails from different people telling that Haiti
# has started DST again today, and this source seems to confirm that,
# I have not been able to find a more authoritative source:
# https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Haiti	1983	only	-	May	8	0:00	1:00	D
Rule	Haiti	1984	1987	-	Apr	lastSun	0:00	1:00	D
Rule	Haiti	1983	1987	-	Oct	lastSun	0:00	0	S
# Shanks & Pottenger say AT is 2:00, but IATA SSIM (1991/1997) says 1:00s.
# Go with IATA.
Rule	Haiti	1988	1997	-	Apr	Sun>=1	1:00s	1:00	D
Rule	Haiti	1988	1997	-	Oct	lastSun	1:00s	0	S
Rule	Haiti	2005	2006	-	Apr	Sun>=1	0:00	1:00	D
Rule	Haiti	2005	2006	-	Oct	lastSun	0:00	0	S
Rule	Haiti	2012	2015	-	Mar	Sun>=8	2:00	1:00	D
Rule	Haiti	2012	2015	-	Nov	Sun>=1	2:00	0	S
Rule	Haiti	2017	max	-	Mar	Sun>=8	2:00	1:00	D
Rule	Haiti	2017	max	-	Nov	Sun>=1	2:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Port-au-Prince -4:49:20 -	LMT	1890
			-4:49	-	PPMT	1917 Jan 24 12:00 # P-a-P MT
			-5:00	Haiti	E%sT

# Honduras
# Shanks & Pottenger say 1921 Jan 1; go with Whitman's more precise Apr 1.

# From Paul Eggert (2006-05-05):
# worldtimezone.com reports a 2006-05-02 Spanish-language AP article
# saying Honduras will start using DST midnight Saturday, effective 4
# months until September.  La Tribuna reported today
# <http://www.latribuna.hn/99299.html> that Manuel Zelaya, the president
# of Honduras, refused to back down on this.

# From Jesper Nørgaard Welen (2006-08-08):
# It seems that Honduras has returned from DST to standard time this Monday at
# 00:00 hours (prolonging Sunday to 25 hours duration).
# http://www.worldtimezone.com/dst_news/dst_news_honduras04.html

# From Paul Eggert (2006-08-08):
# Also see Diario El Heraldo, The country returns to standard time (2006-08-08).
# http://www.elheraldo.hn/nota.php?nid=54941&sec=12
# It mentions executive decree 18-2006.

# From Steffen Thorsen (2006-08-17):
# Honduras will observe DST from 2007 to 2009, exact dates are not
# published, I have located this authoritative source:
# http://www.presidencia.gob.hn/noticia.aspx?nId=47

# From Steffen Thorsen (2007-03-30):
# http://www.laprensahn.com/pais_nota.php?id04962=7386
# So it seems that Honduras will not enter DST this year....

# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Hond	1987	1988	-	May	Sun>=1	0:00	1:00	D
Rule	Hond	1987	1988	-	Sep	lastSun	0:00	0	S
Rule	Hond	2006	only	-	May	Sun>=1	0:00	1:00	D
Rule	Hond	2006	only	-	Aug	Mon>=1	0:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Tegucigalpa -5:48:52 -	LMT	1921 Apr
			-6:00	Hond	C%sT
#
# Great Swan I ceded by US to Honduras in 1972

# Jamaica
# Shanks & Pottenger give -5:07:12, but Milne records -5:07:10.41 from an
# unspecified official document, and says "This time is used throughout the
# island".  Go with Milne.
#
# Shanks & Pottenger give April 28 for the 1974 spring-forward transition, but
# Lance Neita writes that Prime Minister Michael Manley decreed it January 5.
# Assume Neita meant Jan 6 02:00, the same as the US.  Neita also writes that
# Manley's supporters associated this act with Manley's nickname "Joshua"
# (recall that in the Bible the sun stood still at Joshua's request),
# and with the Rod of Correction which Manley said he had received from
# Haile Selassie, Emperor of Ethiopia.  See:
# Neita L. The politician in all of us. Jamaica Observer 2014-09-20
# http://www.jamaicaobserver.com/columns/The-politician-in-all-of-us_17573647
#
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
		#STDOFF	-5:07:10.41
Zone	America/Jamaica	-5:07:10 -	LMT	1890        # Kingston
			-5:07:10 -	KMT	1912 Feb    # Kingston Mean Time
			-5:00	-	EST	1974
			-5:00	US	E%sT	1984
			-5:00	-	EST

# Martinique
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Martinique	-4:04:20 -      LMT	1890        # Fort-de-France
			-4:04:20 -	FFMT	1911 May  1 # Fort-de-France MT
			-4:00	-	AST	1980 Apr  6
			-4:00	1:00	ADT	1980 Sep 28
			-4:00	-	AST

# Nicaragua
#
# This uses Shanks & Pottenger for times before 2005.
#
# From Steffen Thorsen (2005-04-12):
# I've got reports from 8 different people that Nicaragua just started
# DST on Sunday 2005-04-10, in order to save energy because of
# expensive petroleum.  The exact end date for DST is not yet
# announced, only "September" but some sites also say "mid-September".
# Some background information is available on the President's official site:
# http://www.presidencia.gob.ni/Presidencia/Files_index/Secretaria/Notas%20de%20Prensa/Presidente/2005/ABRIL/Gobierno-de-nicaragua-adelanta-hora-oficial-06abril.htm
# The Decree, no 23-2005 is available here:
# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2005/Decreto%2023-2005%20Se%20adelanta%20en%20una%20hora%20en%20todo%20el%20territorio%20nacional%20apartir%20de%20las%2024horas%20del%2009%20de%20Abril.pdf
#
# From Paul Eggert (2005-05-01):
# The decree doesn't say anything about daylight saving, but for now let's
# assume that it is daylight saving....
#
# From Gwillim Law (2005-04-21):
# The Associated Press story on the time change, which can be found at
# http://www.lapalmainteractivo.com/guias/content/gen/ap/America_Latina/AMC_GEN_NICARAGUA_HORA.html
# and elsewhere, says (fifth paragraph, translated from Spanish): "The last
# time that a change of clocks was applied to save energy was in the year 2000
# during the Arnoldo Alemán administration."...
# The northamerica file says that Nicaragua has been on UTC-6 continuously
# since December 1998.  I wasn't able to find any details of Nicaraguan time
# changes in 2000.  Perhaps a note could be added to the northamerica file, to
# the effect that we have indirect evidence that DST was observed in 2000.
#
# From Jesper Nørgaard Welen (2005-11-02):
# Nicaragua left DST the 2005-10-02 at 00:00 (local time).
# http://www.presidencia.gob.ni/presidencia/files_index/secretaria/comunicados/2005/septiembre/26septiembre-cambio-hora.htm
# (2005-09-26)
#
# From Jesper Nørgaard Welen (2006-05-05):
# http://www.elnuevodiario.com.ni/2006/05/01/nacionales/18410
# (my informal translation)
# By order of the president of the republic, Enrique Bolaños, Nicaragua
# advanced by sixty minutes their official time, yesterday at 2 in the
# morning, and will stay that way until 30th of September.
#
# From Jesper Nørgaard Welen (2006-09-30):
# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2006/D-063-2006P-PRN-Cambio-Hora.pdf
# My informal translation runs:
# The natural sun time is restored in all the national territory, in that the
# time is returned one hour at 01:00 am of October 1 of 2006.
#
# Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
Rule	Nic	1979	1980	-	Mar	Sun>=16	0:00	1:00	D
Rule	Nic	1979	1980	-	Jun	Mon>=23	0:00	0	S
Rule	Nic	2005	only	-	Apr	10	0:00	1:00	D
Rule	Nic	2005	only	-	Oct	Sun>=1	0:00	0	S
Rule	Nic	2006	only	-	Apr	30	2:00	1:00	D
Rule	Nic	2006	only	-	Oct	Sun>=1	1:00	0	S
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone	America/Managua	-5:45:08 -	LMT	1890
			-5:45:12 -	MMT	1934 Jun 23 # Managua Mean Time?
			-6:00	-	CST	1973 May
			-5:00	-	EST	1975 Feb 16
			-6:00	Nic	C%sT	1992 Jan  1  4:00
			-5:00	-	EST	1992 Sep 24
			-6:00	-	CST	1993
			-5:00	-	EST	1997
			-6:00	Nic	C%sT

# Cayman Is
# Panama
#
# Atikokan and Coral Harbour, Canada, match Panama since 1970.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone	America/Panama	-5:18:08 -	LMT	1890
			-5:19:36 -	CMT	1908 Apr 22 # Colón Mean Time
			-5:00	-	EST

# Anguilla
# Antigua & Barbuda
# Aruba
# Caribbean Netherlands
# Curaçao
# Dominica
# Grenada
# Guadeloupe
# Montserrat
# Puerto Rico
# St Barthélemy
# St Kitts-Nevis
# Sint Maarten / St Martin
# St Lucia
# St Vincent & the Grenadines
# Trinidad & Tobago
# Virgin Is (UK & US)
#
# There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Puerto_Rico -4:24:25 -	LMT	1899 Mar 28 12:00 # San Juan
			-4:00	-	AST	1942 May  3
			-4:00	US	A%sT	1946
			-4:00	-	AST

# St Pierre and Miquelon
# There are too many St Pierres elsewhere, so we'll use 'Miquelon'.
# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Miquelon	-3:44:40 -	LMT	1911 Jun 15 # St Pierre
			-4:00	-	AST	1980 May
			-3:00	-	%z	1987
			-3:00	Canada	%z

# Turks and Caicos
#
# From Chris Dunn in
# https://bugs.debian.org/415007
# (2007-03-15): In the Turks & Caicos Islands (America/Grand_Turk) the
# daylight saving dates for time changes have been adjusted to match
# the recent U.S. change of dates.
#
# From Brian Inglis (2007-04-28):
# http://www.turksandcaicos.tc/calendar/index.htm [2007-04-26]
# there is an entry for Nov 4 "Daylight Savings Time Ends 2007" and three
# rows before that there is an out of date entry for Oct:
# "Eastern Standard Times Begins 2007
# Clocks are set back one hour at 2:00 a.m. local Daylight Saving Time"
# indicating that the normal ET rules are followed.

# From Paul Eggert (2014-08-19):
# The 2014-08-13 Cabinet meeting decided to stay on UT -04 year-round.  See:
# http://tcweeklynews.com/daylight-savings-time-to-be-maintained-p5353-127.htm
# Model this as a switch from EST/EDT to AST ...
# From Chris Walton (2014-11-04):
# ... the TCI government appears to have delayed the switch to
# "permanent daylight saving time" by one year....
# http://tcweeklynews.com/time-change-to-go-ahead-this-november-p5437-127.htm
#
# From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
# ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
# during the summer months and Standard Time, also known as Local
# Time, during the winter months with effect from April 2018 ...
# https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-statement--3
# From Paul Eggert (2017-08-26):
# The date of effect of the spring 2018 change appears to be March 11,
# which makes more sense.  See: Hamilton D. Time change back
# by March 2018 for TCI. Magnetic Media. 2017-08-25.
# http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/
#
# From P Chan (2020-11-27):
# Standard Time Declaration Order 2015 (L.N. 15/2015)
# http://online.fliphtml5.com/fizd/czin/#p=2
#
# Standard Time Declaration Order 2017 (L.N. 31/2017)
# http://online.fliphtml5.com/fizd/dmcu/#p=2
#
# From Tim Parenti (2020-12-05):
# Although L.N. 31/2017 reads that it "shall come into operation at 2:00 a.m.
# on 11th March 2018", a precise interpretation here poses some problems.  The
# order states that "the standard time to be observed throughout the Turks and
# Caicos Islands shall be the same time zone as the Eastern United States of
# America" and further clarifies "[f]or the avoidance of doubt" that it
# "applies to the Eastern Standard Time as well as any changes thereto for
# Daylight Saving Time."  However, as clocks in Turks and Caicos approached
# 02:00 -04, and thus the declared implementation time, it was still 01:00 EST
# (-05), as DST in the Eastern US would not start until an hour later.
#
# Since it is unlikely that those on the islands switched their clocks twice in
# the span of an hour, we assume instead that the adoption of EDT actually took
# effect once clocks in the Eastern US had sprung forward, from 03:00 -04.
# This discrepancy only affects the time zone abbreviation and DST flag for the
# intervening hour, not wall clock times, as -04 was maintained throughout.

# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
Zone America/Grand_Turk	-4:44:32 -	LMT	1890
		#STDOFF	-5:07:10.41
			-5:07:10 -	KMT	1912 Feb # Kingston Mean Time
			-5:00	-	EST	1979
			-5:00	US	E%sT	2015 Mar  8  2:00
			-4:00	-	AST	2018 Mar 11  3:00
			-5:00	US	E%sT

# Local Variables:
# coding: utf-8
# End: