path: root/time/northamerica

# @(#)northamerica	7.31
# also includes Central America and the Caribbean

# This data is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@elsie.nci.nih.gov for general use in the future).

# From Paul Eggert <eggert@twinsun.com> (1994-08-17):
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and the discovery of the longitude,
# Oxford University Press (1980).

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

# United States

# From Paul Eggert <eggert@twinsun.com> (1995-12-19):
# 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 the US and Puerto Rico entries below.

# From Paul Eggert (1996-06-12):
# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
# in his whimsical essay ``Turkey vs Eagle, McCauley is my Beagle'' (1784).
# 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 (1947), XIX, Sunday

# From Arthur David Olson:
# US Daylight Saving Time ended on the last Sunday of *October* in 1974.
# See, for example, the front page of the Saturday, 1974-10-26
# and Sunday, 1974-10-27 editions of the Washington Post.

# 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.

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	US	1918	1919	-	Mar	lastSun	2:00	1:00	W # War
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	-	Sep	30	2:00	0	S
Rule	US	1967	max	-	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	23	2:00	1:00	D
Rule	US	1976	1986	-	Apr	lastSun	2:00	1:00	D
Rule	US	1987	max	-	Apr	Sun>=1	2:00	1:00	D

# From Bob Devine (1988-01-28):
# ...Alaska (and Hawaii) had the timezone names changed in 1967.
#    old			 new
#    Pacific Standard Time(PST)  -same-
#    Yukon Standard Time(YST)    -same-
#    Central Alaska S.T. (CAT)   Alaska-Hawaii St[an]dard Time (AHST)
#    Nome Standard Time (NT)     Bering Standard Time (BST)
#
# ...Alaska's timezone lines were redrawn in 1983 to give only 2 tz.
#    The YST zone now covers nearly all of the state, AHST just part
#    of the Aleutian islands.   No DST.

# From Paul Eggert (1995-12-19):
# The tables below use `NST', not `NT', for Nome Standard Time.
# I invented `CAWT' for Central Alaska War Time.

# 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 (1995-12-19):
# Shanks uses 1983-10-30, not 1983-11-30, for the 1983 transitions.
# Go with Shanks.

# US Eastern time, represented by New York
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/New_York	-4:56:02 -	LMT	1883 Nov 18 12:00
			-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
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Chicago	-5:50:36 -	LMT	1883 Nov 18 12:00
			-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

# US Mountain time, represented by Denver
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Denver	-6:59:56 -	LMT	1883 Nov 18 12:00
			-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
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER
Rule	CA	1948	only	-	Mar	14	2:00	1:00	D
Rule	CA	1949	only	-	Jan	 1	2:00	0	S
Rule	CA	1950	1966	-	Apr	lastSun	2:00	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Los_Angeles -7:52:58 -	LMT	1883 Nov 18 12:00
			-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 -9:00 per USNO.
#
# From Paul Eggert (1995-12-19):
# 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.
# This was on 1867-10-18.  We omit this transition, since we can't represent
# changes from Julian to Gregorian.
#
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Juneau	 -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	1983 Oct 30 2:00
			 -9:00	US	AK%sT
Zone America/Yakutat	 -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 Oct 30 2:00
			 -9:00	US	AK%sT
Zone America/Anchorage	 -9:59:36 -	LMT	1900 Aug 20 12:00
			-10:00	-	CAT	1942
			-10:00	US	CAT/CAWT 1946
			-10:00	-	CAT	1967 Apr
			-10:00	-	AHST	1969
			-10:00	US	AH%sT	1983 Oct 30 2:00
			 -9:00	US	AK%sT
Zone America/Nome	-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	AK%sT
Zone America/Adak	-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	HA%sT
# 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.
# These switches don't quite make our 1970 cutoff.

# Hawaii
#
# From Arthur David Olson:
# And then there's Hawaii.
# DST was observed for one day in 1933;
# standard time was changed by half an hour in 1947;
# it's always standard as of 1986.
#
# From Paul Eggert:
# Shanks says the 1933 experiment lasted for three weeks.  Go with Shanks.
#
Zone Pacific/Honolulu	-10:31:26 -	LMT	1900 Jan  1 12:00
			-10:30	-	HST	1933 Apr 30 2:00
			-10:30	1:00	HDT	1933 May 21 2:00
			-10:30	US	H%sT	1947 Jun  8 2:00
			-10:00	-	HST

Zone Pacific/Midway	-11:49:28 -	LMT	1901
			-11:00	-	NST	1967 Apr	# N=Nome
			-11:00	-	BST	1983 Nov 30	# B=Bering
			-11:00	-	SST			# S=Samoa

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

# Arizona mostly uses MST.
Zone America/Phoenix	-7:28:18 -	LMT	1883 Nov 18 12:00
			-7:00	US	M%sT	1944 Jan  1 00:01
			-7:00	-	MST	1944 Mar 17 00:01
			-7:00	US	M%sT	1944 Oct  1 00:01
			-7:00	-	MST	1967
			-7:00	US	M%sT	1968
			-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 12/28/87 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.)

Link America/Denver America/Shiprock

# Southern Idaho and eastern Oregon switched four weeks late in 1974.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Boise	-7:44:49 -	LMT	1883 Nov 18 12:00
			-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
#
# From Paul Eggert (1995-12-19):
# Indiana generally observes either EST all year, or CST/CDT,
# but areas near Cincinnati and Louisville use those cities' timekeeping
# and in 1969 and 1970 the whole state observed daylight time;
# and there are other exceptions as noted below.
# Shanks partitions Indiana into 345 regions, each with its own time history,
# and writes ``Even newspaper reports present contradictory information.''
# Fortunately, most of the complexity occurred before our cutoff date of 1970.
#
# Since 1970, EST-only Indiana has been like America/Indianapolis,
# with exceptions noted below for Crawford, Starke, and Switzerland counties.
# The parts of Indiana not listed below have been like America/Chicago,
# America/Louisville, or America/New_York.
#
# 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'.
#
# Most of EST-only Indiana last observed DST in 1970.
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:00
			-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
Link America/Indianapolis America/Indiana/Indianapolis
#
# Part of Crawford County, Indiana, last observed DST in 1975,
# and left its clocks alone in 1974.
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Marengo -5:45:23 -	LMT	1883 Nov 18 12:00
			-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
#
# Starke County, Indiana
# 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	TYPE	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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Knox -5:46:30 -	LMT	1883 Nov 18 12:00
			-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
#
# Switzerland County, Indiana, last observed DST in 1972.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Indiana/Vevay -5:40:16 -	LMT	1883 Nov 18 12:00
			-6:00	US	C%sT	1954 Apr 25 2:00
			-5:00	-	EST	1969
			-5:00	US	E%sT	1973
			-5:00	-	EST

# Part of Kentucky left its clocks alone in 1974.
# Rule	NAME	FROM	TO	TYPE	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	1961	-	Apr	lastSun	2:00	1:00	D
Rule Louisville	1941	only	-	Sep	lastSun	2:00	0	S
Rule Louisville	1946	only	-	Jun	2	2:00	0	S
Rule Louisville	1950	1955	-	Sep	lastSun	2:00	0	S
Rule Louisville	1956	1960	-	Oct	lastSun	2:00	0	S
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Louisville	-5:43:02 -	LMT	1883 Nov 18 12:00
			-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

# Michigan
#
# From Bob Devine (1988-01-28):
# Michigan didn't observe DST from 1968 to 1973.
#
# From Paul Eggert (1995-12-19):
# Shanks writes that Michigan started using standard time on 1885 Sep 18,
# but Howse (p 126) writes 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.
#
# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
# Rule	NAME	FROM	TO	TYPE	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
Rule	Detroit	1967	only	-	Jun	14	2:00	1:00	D
Rule	Detroit	1967	only	-	Oct	lastSun	2:00	0	S
# Zone	NAME		GMTOFF	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	1973
			-5:00	US	E%sT	1975
			-5:00	-	EST	1975 Apr 27 2:00
			-5:00	US	E%sT
#
# The Michigan border with Wisconsin switched from EST to CST/CDT in 1973.
# Rule	NAME	FROM	TO	TYPE	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		GMTOFF	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
# uninhabited


# Old names, for S5 users

# Link	LINK-FROM		LINK-TO
Link	America/New_York	EST5EDT
Link	America/Chicago		CST6CDT
Link	America/Denver		MST7MDT
Link	America/Los_Angeles	PST8PDT
Link	America/Indianapolis	EST
Link	America/Phoenix		MST
Link	Pacific/Honolulu	HST

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


# From Paul Eggert <eggert@twinsun.com> (1996-11-22):
# A good source for time zone historical data outside the US is
# Thomas G. Shanks, The International Atlas (3rd edition),
# San Diego: ACS Publications, Inc. (1991).
#
# Gwillim Law <LAW@encmail.encompass.com> writes that a good source
# for recent time zone data is 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, Shanks is the source for entries through 1990,
# and IATA SSIM is the source for entries after 1990.
#
# Another source occasionally used is Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
# I found in the UCLA library.
#
# See the `europe' file for Greenland.
#
# See the `africa' file for time zone naming and abbreviation conventions.

# Canada

# From Alain LaBont<e'> <ALB@immedia.ca> (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 savings 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 Avanc<e'>e	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 <eggert@twinsun.com> (1994-11-22):
# Alas, this sort of thing must be handled by localization software.

# The data for Canada are all from Shanks (1991).


# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Canada	1918	only	-	Apr	14	2:00	1:00	D
Rule	Canada	1918	only	-	Oct	31	2:00	0	S
Rule	Canada	1942	only	-	Feb	 9	2:00	1:00	D
Rule	Canada	1945	only	-	Sep	30	2:00	0	S
Rule	Canada	1974	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Canada	1974	max	-	Oct	lastSun	2:00	0	S
Rule	Canada	1987	max	-	Apr	Sun>=1	2:00	1:00	D


# Newfoundland (except Labrador)

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	StJohns	1917	1918	-	Apr	Sun>=8	2:00	1:00	D
Rule	StJohns	1917	only	-	Sep	17	2:00	0	S
Rule	StJohns	1918	only	-	Oct	31	2:00	0	S
# Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks.
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.
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 Shanks gives May Mon>=9 and Oct Mon>=2; go with Whitman.
Rule	StJohns	1936	1941	-	May	Sun>=8	0:00	1:00	D
Rule	StJohns	1936	1941	-	Oct	Sun>=1	0:00	0	S
# Shanks gives 1942 May 11 - 1945 Sep 30; go with Whitman.
Rule	StJohns	1942	only	-	Mar	 1	0:00	1:00	D
Rule	StJohns	1942	only	-	Dec	31	0:00	0	S
Rule	StJohns	1943	only	-	May	30	0:00	1:00	D
Rule	StJohns	1943	only	-	Sep	 5	0:00	0	S
Rule	StJohns	1944	only	-	Jul	10	0:00	1:00	D
Rule	StJohns	1944	only	-	Sep	 2	0:00	0	S
Rule	StJohns	1945	only	-	Jan	 1	0:00	1:00	D
Rule	StJohns	1945	only	-	Oct	 7	2:00	0	S
# 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.
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	max	-	Oct	lastSun	2:00	0	S
Rule	StJohns	1987	only	-	Apr	Sun>=1	2:00	1:00	D
Rule	StJohns	1988	only	-	Apr	Sun>=1	2:00	2:00	DD
Rule	StJohns	1989	max	-	Apr	Sun>=1	2:00	1:00	D
# St John's has an apostrophe, but Posix file names can't have apostrophes.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Johns	-3:30:52 -	LMT	1884
			-3:30:52 StJohns N%sT	1935 Mar 30
			-3:30	StJohns	N%sT


# east Labrador

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


# west Labrador, New Brunswick, Nova Scotia, Prince Edward I

# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like Halifax.
# Many locales did not observe peacetime DST until 1972;
# Glace Bay, NS is the largest that we know of.
# Shanks also writes 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.

# Rule	NAME	FROM	TO	TYPE	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	1918	only	-	Apr	14	2:00	1:00	D
Rule Halifax	1918	only	-	Oct	31	2:00	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	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	1942	only	-	Feb	9	2:00	1:00	D
Rule Halifax	1945	1959	-	Sep	lastSun	2:00	0	S
Rule Halifax	1946	1959	-	Apr	lastSun	2:00	1:00	D
Rule Halifax	1962	1986	-	Apr	lastSun	2:00	1:00	D
Rule Halifax	1962	max	-	Oct	lastSun	2:00	0	S
Rule Halifax	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Halifax	-4:14:24 -	LMT	1902 Jun 15
			-4:00	Halifax	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


# Ontario, Quebec

# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like Montreal.
# Thunder Bay skipped DST in 1973.
# Many smaller locales did not observe peacetime DST until 1974;
# Nipigon (EST) and Rainy River (CST) are the largest that we know of.
# Far west Ontario is like Winnipeg; far east Quebec is like Halifax.

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Mont	1917	only	-	Mar	25	2:00	1:00	D
Rule	Mont	1917	only	-	Apr	24	0:00	0	S
Rule	Mont	1918	only	-	Apr	14	2:00	1:00	D
Rule	Mont	1918	only	-	Oct	31	2:00	0	S
Rule	Mont	1919	only	-	Mar	31	2:30	1:00	D
Rule	Mont	1919	only	-	Oct	25	2:30	0	S
Rule	Mont	1920	only	-	May	 2	2:30	1:00	D
Rule	Mont	1920	only	-	Oct	 3	2:30	0	S
Rule	Mont	1921	only	-	May	 1	2:00	1:00	D
Rule	Mont	1921	only	-	Oct	 2	2:30	0	S
Rule	Mont	1922	only	-	Apr	30	2:00	1:00	D
Rule	Mont	1922	only	-	Oct	 1	2:30	0	S
Rule	Mont	1924	only	-	May	17	2:00	1:00	D
Rule	Mont	1924	1926	-	Sep	lastSun	2:30	0	S
Rule	Mont	1925	1926	-	May	Sun>=1	2:00	1:00	D
Rule	Mont	1927	only	-	May	 1	0:00	1:00	D
Rule	Mont	1927	1932	-	Sep	Sun>=25	0:00	0	S
Rule	Mont	1928	1931	-	Apr	Sun>=25	0:00	1:00	D
Rule	Mont	1932	only	-	May	 1	0:00	1:00	D
Rule	Mont	1933	1940	-	Apr	Sun>=24	0:00	1:00	D
Rule	Mont	1933	only	-	Oct	 1	0:00	0	S
Rule	Mont	1934	1939	-	Sep	Sun>=24	0:00	0	S
Rule	Mont	1945	1948	-	Sep	lastSun	2:00	0	S
Rule	Mont	1946	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Mont	1949	1950	-	Oct	lastSun	2:00	0	S
Rule	Mont	1951	1956	-	Sep	lastSun	2:00	0	S
Rule	Mont	1957	max	-	Oct	lastSun	2:00	0	S
Rule	Mont	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Montreal	-4:54:16 -	LMT	1884
			-5:00	Mont	E%sT
Zone America/Thunder_Bay -5:57:00 -	LMT	1895
			-5:00	Canada	E%sT	1970
			-5:00	Mont	E%sT	1973
			-5:00	-	EST	1974
			-5:00	Canada	E%sT
Zone America/Nipigon	-5:53:04 -	LMT	1895
			-5:00	Canada	E%sT
Zone America/Rainy_River -6:17:56 -	LMT	1895
			-6:00	Canada	C%sT


# Manitoba

# Rule	NAME	FROM	TO	TYPE	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	31	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	D
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	2:00	1:00	D
Rule	Winn	1966	max	-	Oct	lastSun	2:00	0	S
Rule	Winn	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Winnipeg	-6:28:36 -	LMT	1887 Jul 16
			-6:00	Winn	C%sT


# Saskatchewan

# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like 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.

# From W. Jones <jones@skdad.usask.ca> (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.

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Regina	1918	only	-	Apr	14	2:00	1:00	D
Rule	Regina	1918	only	-	Oct	31	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	D
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	1959	-	Apr	lastSun	2:00	1:00	D
Rule	Regina	1947	1958	-	Sep	lastSun	2:00	0	S
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		GMTOFF	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

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Edm	1918	1919	-	Apr	Sun>=8	2:00	1:00	D
Rule	Edm	1918	only	-	Oct	31	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	D
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	1967	only	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1967	only	-	Oct	lastSun	2:00	0	S
Rule	Edm	1969	only	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1969	only	-	Oct	lastSun	2:00	0	S
Rule	Edm	1972	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Edm	1972	max	-	Oct	lastSun	2:00	0	S
Rule	Edm	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Edmonton	-7:33:52 -	LMT	1906 Sep
			-7:00	Edm	M%sT


# British Columbia

# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like Vancouver.
# Dawswon Creek uses MST.  Much of east BC is like Edmonton.

# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Vanc	1918	only	-	Apr	14	2:00	1:00	D
Rule	Vanc	1918	only	-	Oct	31	2:00	0	S
Rule	Vanc	1942	only	-	Feb	 9	2:00	1:00	D
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	-	Oct	13	2:00	0	S
Rule	Vanc	1947	1961	-	Sep	lastSun	2:00	0	S
Rule	Vanc	1962	max	-	Oct	lastSun	2:00	0	S
Rule	Vanc	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Vancouver	-8:12:28 -	LMT	1884
			-8:00	Vanc	P%sT
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


# Northwest Territories, Yukon

# From Paul Eggert (1996-10-07):
# Dawson switched to PST in 1973.  Inuvik switched to MST in 1979.
# Shanks's table for Watson Lake is corrupted, so we have no data there.
# Mathew Englander <mathew@io.org> (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.  This is still valid;
#	see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
#	* 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.
# Shanks says Yukon's 1973-10-28 switch was at 2:00; go with Englander.

# Rule	NAME	FROM	TO	TYPE	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	D
Rule	NT_YK	1945	only	-	Sep	30	2:00	0	S
Rule	NT_YK	1965	only	-	Apr	lastSun	0:00	2:00	DD
Rule	NT_YK	1965	only	-	Oct	lastSun	2:00	0	S
Rule	NT_YK	1980	1986	-	Apr	lastSun	2:00	1:00	D
Rule	NT_YK	1980	max	-	Oct	lastSun	2:00	0	S
Rule	NT_YK	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Pangnirtung -4:22:56 -	LMT	1884
			-4:00	NT_YK	A%sT
Zone America/Iqaluit	-4:33:52 -	LMT	1884	# Frobisher Bay
			-5:00	NT_YK	E%sT
Zone America/Rankin_Inlet -6:08:40 -	LMT	1884
			-6:00	NT_YK	C%sT
Zone America/Yellowknife -7:37:24 -	LMT	1884
			-7:00	NT_YK	M%sT
Zone America/Inuvik	-8:54:00 -	LMT	1884
			-8:00	NT_YK	P%sT	1979 Apr lastSun 2:00
			-7:00	NT_YK	M%sT
Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
			-9:00	NT_YK	Y%sT	1966 Jul 1 2:00
			-8:00	NT_YK	P%sT
Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
			-9:00	NT_YK	Y%sT	1973 Oct 28 0:00
			-8:00	NT_YK	P%sT


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

# Mexico

# From Guy Harris:
# Rules are from the Official Airline Guide, Worldwide Edition, for 1987.
# Rules prior to 1987 are unknown.
# The comments in the OAG say "Only Ensenada, Mexicale, San Felipe and Tijuana
# observe DST."  This is presumably Baja California Norte, above 28th parallel,
# as listed there; [there is also] "Baja California Sur and N. Pacific
# Coast (States of Sinaloa and Sonora)."

# From Bob Devine (1988-01-28):
# The Federal District (where Mexico City is) has observed [DST] several
# times but not recently.
#
# I don't where to drawn the line in the North Baja area.  28th latitude
# sounds good -- but it may be higher (how far [d]o radio stations from
# San Diego affect culture?).
#
# The dates of DST probably go back to 1981.  The rules are the same as
# US's.  This is going to be a headache for US presidential electi[o]n years!

# From Arthur David Olson (1988-02-13)
# Since the 1981 starting date is only "probable," we'll keep the 1987
# starting date below.

# From U. S. Naval Observatory (1989-01-19):
# MEXICO BAJA CAL N   7 H  BEHIND UTC    BAJA CALIFORNIA SUR AND
# MEXICO BAJA CAL N                      N. PACIFIC COAST (STATES
# MEXICO BAJA CAL N                      OF SINALOA AND SONORA)
# MEXICO BAJA CAL N   8 H  BEHIND UTC    ABOVE 28TH PARALLEL APR 3
# MEXICO BAJA CAL N                      - OCT 29
# MEXICO BAJA CAL N   7 H  BEHIND UTC    ABOVE 28TH PARALLEL APR 3
# MEXICO BAJA CAL N                      - 0CT 29
# MEXICO              6 H  BEHIND UTC    STATES OF DURANGO,
# MEXICO                                 COAHUILA, NUEVO LEON,
# MEXICO                                 TAMAULIPAS
# MEXICO              5 H  BEHIND UTC    STATES OF DURANGO,
# MEXICO                                 COAHUILA, NUEVO LEON,
# MEXICO                                 TAMAULIPAS  APR 3 - OCT 29
# MEXICO              6 H  BEHIND UTC    GENERAL MEXICO, STATES OF
# MEXICO                                 CAMPECHE, QUINTANA ROO AND
# MEXICO                                 YUCATAN

# From Arthur David Olson (1989-01-21):
# April 3 fell on a Sunday in 1988; October 29 fell on a Sunday in 1989.  Ahem.
# USNO claims there should be four Mexican zones rather than three:
# a zone that's GMT-8 with DST; a zone that's always GMT-7;
# a zone that's GMT-6 with DST; and a zone that's always GMT-6.

# From Paul Eggert <eggert@twinsun.com> (1993-11-18):
# Shanks also says there are four zones, but disagrees about the fourth.
# Instead of GMT-6 with DST, he says there's GMT-8 without DST.

# From Alan Perry <alan.perry@eng.sun.com> (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'',
# <URL:http://mexico-travel.com/extra/timezone_eng.html> (1996-01-04).

# From Shanks (1991):
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/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	D
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	max	-	Apr	Sun>=1	2:00	1:00	D
Rule	Mexico	1996	max	-	Oct	lastSun	2:00	0	S
#
Rule	BajaN	1950	1966	-	Apr	lastSun	2:00	1:00	D
Rule	BajaN	1950	1961	-	Sep	lastSun	2:00	0	S
Rule	BajaN	1961	1966	-	Oct	lastSun	2:00	0	S
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  0:23:24
			-7:00	-	MST	1927 Jun 10 23:00
			-6:00	-	CST	1930 Nov 15
			-7:00	-	MST	1931 May  1 23:00
			-6:00	-	CST	1931 Oct
			-7:00	-	MST	1932 Mar 30 23:00
			-6:00	Mexico	C%sT
Zone America/Mazatlan	-7:05:40 -	LMT	1921 Dec 31 23:54:20
			-7:00	-	MST	1927 Jun 10 23:00
			-6:00	-	CST	1930 Nov 15
			-7:00	-	MST	1931 May  1 23:00
			-6:00	-	CST	1931 Oct
			-7:00	-	MST	1932 Mar 30 23:00
			-6:00	-	CST	1942 Apr
			-7:00	-	MST	1949 Jan 14
			-8:00	-	PST	1970
			-7:00	Mexico	M%sT
Zone America/Tijuana	-7:48:04 -	LMT	1922 Jan  1  0:11:56
			-8:00	-	PST	1927 Jun 10 23:00
			-7:00	-	MST	1930 Nov 16
			-8:00	-	PST	1942 Apr
			-7:00	-	MST	1949 Jan 14
			-8:00	BajaN	P%sT	1967 Apr lastSun 2:00
			-8:00	US	P%sT	1996
			-8:00	Mexico	P%sT
Zone America/Ensenada	-7:46:28 -	LMT	1922 Jan  1  0:13:32
			-8:00	-	PST	1927 Jun 10 23:00
			-7:00	-	MST	1930 Nov 16
			-8:00	-	PST	1942 Apr
			-7:00	-	MST	1949 Jan 14
			-8:00	-	PST	1996
			-8:00	Mexico	P%sT
#
# Revillagigedo Is
# no information

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

# Anguilla
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Anguilla	-4:12:16 -	LMT	1912 Mar 2
			-4:00	-	AST

# Antigua and Barbuda
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Antigua	-4:07:12 -	LMT	1912 Mar 2
			-5:00	-	EST	1951
			-4:00	-	AST

# Bahamas
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Bahamas	1964	max	-	Oct	lastSun	2:00	0	S
Rule	Bahamas	1964	1986	-	Apr	lastSun	2:00	1:00	D
Rule	Bahamas	1987	max	-	Apr	Sun>=1	2:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Nassau	-5:09:24 -	LMT	1912 Mar 2
			-5:00	Bahamas	E%sT

# Barbados
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/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		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Barbados	-3:58:28 -	LMT	1924		# Bridgetown
			-3:58	-	BMT	1932	  # Bridgetown Mean Time
			-4:00	Barb	A%sT

# Belize
# Whitman entirely disagrees with Shanks; go with Shanks.
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	Belize	1918	1942	-	Oct	Sun>=2	0:00	0:30	HD
Rule	Belize	1919	1943	-	Feb	Sun>=9	0:00	0	S
Rule	Belize	1973	only	-	Dec	 5	0:00	1:00	D
Rule	Belize	1974	only	-	Feb	 9	0:00	0	S
Rule	Belize	1982	only	-	Dec	18	0:00	1:00	D
Rule	Belize	1983	only	-	Feb	12	0:00	0	S
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Belize	-5:52:48 -	LMT	1912 Apr
			-6:00	Belize	C%sT

# Bermuda
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone Atlantic/Bermuda	-4:19:04 -	LMT	1930 Jan  1 2:00    # Hamilton
			-4:00	-	AST	1974 Apr 28 2:00
			-4:00	Bahamas	A%sT

# Cayman Is
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Cayman	-5:25:32 -	LMT	1890		# Georgetown
			-5:07	-	KMT	1912 Feb    # Kingston Mean Time
			-5:00	-	EST

# Clipperton
# uninhabited

# Costa Rica
# Shanks gives some very odd dates for 1991, and stops there.
# For now, we won't guess further.
# Rule	NAME	FROM	TO	TYPE	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.
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 Joses elsewhere, so we'll use `Costa Rica'.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Costa_Rica	-5:36:20 -	LMT	1890		# San Jose
			-5:36	-	SJMT	1921 Jan 15 # San Jose Mean Time
			-6:00	CR	C%sT
# Coco
# no information; probably like America/Costa_Rica

# Cuba

# From Bob Devine (1988-01-28):
# . . .DST is from 2nd Sunday in May to 2nd Sunday in October since 1981.
# Change at midnight.  In 1979 & 1980, started at 3rd Sunday in March
# (I think).

# From U. S. Naval Observatory (1989-01-19):
# CUBA                5 H  BEHIND UTC
# CUBA                4 H  BEHIND UTC    MAR 20 - OCT 8

# From Shanks (1991):
# Rule	NAME	FROM	TO	TYPE	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	max	-	Apr	Sun>=1	0:00	1:00	D
Rule	Cuba	1991	1995	-	Oct	Sun>=8	0:00s	0	S
Rule	Cuba	1996	only	-	Oct	Sun>=1	0:00s	0	S
Rule	Cuba	1997	max	-	Oct	Sun>=8	0:00s	0	S

# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Havana	-5:29:28 -	LMT	1890
			-5:30	-	HMT	1925 Jul 19 12:00 # Havana MT
			-5:00	Cuba	C%sT

# Dominica
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Dominica	-4:05:36 -	LMT	1911 Jul 1 0:01		# Roseau
			-4:00	-	AST

# Dominican Republic
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	DR	1966	only	-	Oct	30	0:00	1:00	D
Rule	DR	1967	only	-	Feb	28	0:00	0	S
Rule	DR	1969	1973	-	Oct	lastSun	0:00	0:30	HD
Rule	DR	1970	only	-	Feb	21	0:00	0	S
Rule	DR	1971	only	-	Jan	20	0:00	0	S
Rule	DR	1972	1974	-	Jan	21	0:00	0	S
# Zone	NAME		GMTOFF	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	E%sT	1974 Oct 27
			-4:00	-	AST

# El Salvador
# Rule	NAME	FROM	TO	TYPE	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 we'll use `El Salvador'.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/El_Salvador -5:56:48 -	LMT	1921		# San Salvador
			-6:00	Salv	C%sT

# Grenada
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Grenada	-4:07:00 -	LMT	1911 Jul	# St George's
			-4:00	-	AST

# Guadeloupe
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Guadeloupe	-4:06:08 -	LMT	1911 Jun 8	# Pointe a Pitre
			-4:00	-	AST

# Guatemala
# Rule	NAME	FROM	TO	TYPE	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
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Guatemala	-6:02:04 -	LMT	1918 Oct 5
			-6:00	Guat	C%sT

# Haiti
# Rule	NAME	FROM	TO	TYPE	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 says AT is 2:00, but IATA SSIM (1991/1996) says 1:00s.  Go with IATA.
Rule	Haiti	1988	max	-	Apr	Sun>=1	1:00s	1:00	D
Rule	Haiti	1988	max	-	Oct	lastSun	1:00s	0	S
# Zone	NAME		GMTOFF	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 says 1921 Jan 1; go with Whitman's more precise Apr 1.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Tegucigalpa -5:48:52 -	LMT	1921 Apr
			-6:00	Salv	C%sT

# Jamaica

# From Bob Devine (1988-01-28):
# Follows US rules.

# From U. S. Naval Observatory (1989-01-19):
# JAMAICA             5 H  BEHIND UTC

# From Shanks (1991):
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Jamaica	-5:07:12 -	LMT	1890		# Kingston
			-5:07	-	KMT	1912 Feb    # Kingston Mean Time
			-5:00	-	EST	1974 Jan 6 2:00
			-5:00	US	E%sT	1984
			-5:00	-	EST

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

# Montserrat
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Montserrat	-4:08:52 -	LMT	1911 Jul 1 0:01   # Plymouth
			-4:00	-	AST

# Nicaragua
# Rule	NAME	FROM	TO	TYPE	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	1992	only	-	Jan	1	4:00	1:00	D
Rule	Nic	1992	only	-	Sep	24	0:00	0	S
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Managua	-5:45:08 -	LMT	1890
			-5:45	-	MMT	1934 Jun 23  # Managua Mean Time
			-6:00	-	CST	1973 May
			-5:00	-	EST	1975 Feb 16
			-6:00	Nic	C%sT	1993 Jan 1 4:00
			-5:00	-	EST

# Panama
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone	America/Panama	-5:18:08 -	LMT	1890
			-5:20	-	PMT	1908 Apr 22   # Panama Mean Time
			-5:00	-	EST

# Puerto Rico
# There are too many San Juans elsewhere, so we'll use `Puerto_Rico'.
# Zone	NAME		GMTOFF	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	1:00	AWT	1945 Sep 30  2:00
			-4:00	-	AST

# St Kitts-Nevis
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Kitts	-4:10:52 -	LMT	1912 Mar 2	# Basseterre
			-4:00	-	AST

# St Lucia
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Lucia	-4:04:00 -	LMT	1890		# Castries
			-4:04	-	CMT	1912	    # Castries Mean Time
			-4:00	-	AST

# St Pierre and Miquelon
# There are too many St Pierres elsewhere, so we'll use `Miquelon'.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Miquelon	-3:44:40 -	LMT	1911 May 15	# St Pierre
			-4:00	-	AST	1980 May
			-3:00	Mont	PM%sT	# Pierre & Miquelon Time

# St Vincent and the Grenadines
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Vincent	-4:04:56 -	LMT	1890		# Kingstown
			-4:05	-	KMT	1912	   # Kingstown Mean Time
			-4:00	-	AST

# Turks and Caicos
# From Paul Eggert (1996-11-22):
# Shanks says they use US DST rules, but IATA SSIM (1991/1996)
# says they switch at midnight.  Go with IATA SSIM.
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
Rule	TC	1979	1986	-	Apr	lastSun	0:00	1:00	D
Rule	TC	1979	max	-	Oct	lastSun	0:00	0	S
Rule	TC	1987	max	-	Apr	Sun>=1	0:00	1:00	D
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Grand_Turk	-4:44:32 -	LMT	1890
			-5:07	-	KMT	1912 Feb    # Kingston Mean Time
			-5:00	TC	E%sT

# British Virgin Is
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Tortola	-4:18:28 -	LMT	1911 Jul    # Road Town
			-4:00	-	AST

# Virgin Is
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/St_Thomas	-4:19:44 -	LMT	1911 Jul    # Charlotte Amalie
			-4:00	-	AST