1 files changed, 209 insertions, 128 deletions

diff --git a/share/zoneinfo/northamerica b/share/zoneinfo/northamerica
index d1427900ddc1..57719816f9bb 100644
--- a/share/zoneinfo/northamerica
+++ b/share/zoneinfo/northamerica
@@ -1,4 +1,4 @@
-# @(#)northamerica	7.22
+# @(#)northamerica	7.26
 # also includes Central America and the Caribbean
 
 # This data is by no means authoritative; if you think you know better,
@@ -21,6 +21,24 @@
 # 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, October 26, 1974
@@ -160,11 +178,11 @@ 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	E%sT	1920
-			-7:00	Denver	E%sT	1942
-			-7:00	US	E%sT	1946
-			-7:00	Denver	E%sT	1967
-			-7:00	US	E%sT
+			-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
@@ -461,82 +479,8 @@ Link	Pacific/Honolulu	HST
 #
 # See the `africa' file for Zone naming conventions.
 
-
-
 # Canada
 
-# Canada is reportedly lots easier than the US--leastways since 1951.
-# I don't know what they did before then.
-# 4.3BSD claims that it's perfectly regular.
-# According to a posting in "comp.bugs.misc", "comp.unix.wizards", etc.
-# on February 8, 1987, by Dave Sherman of the Law Society of Upper Canada,
-# "...Canada (well, Ontario and at least some of the other provinces) are
-# adopting the new daylight savings time rules...".  We assume all of
-# Canada is doing so.
-
-# From Bob Devine (January 28, 1988):
-# All of Canada did have DST from your first rule except Saskatchewan.
-# Which parts did not observe DST is hard to pinpoint but most of the
-# province follows the rules.
-# NOTE: those that didn't have DST for that rule, also
-# probably did not have it for several years previous.
-
-# From U. S. Naval Observatory (January 19, 1989):
-# CANADA   NEW FDL    3.5H BEHIND UTC    ST.JOHN'S
-# CANADA   NEW FDL    1.5H BEHIND UTC    APR 3 - OCT 29
-# CANADA   ATLANTIC   4 H  BEHIND UTC    HALIFAX
-# CANADA   ATLANTIC   3 H  BEHIND UTC    APR 3 - OCT 29
-# CANADA   EASTERN    5 H  BEHIND UTC    TORONTO, MONTREAL, OTTAWA
-# CANADA   EASTERN    4 H  BEHIND UTC    APR 3 - OCT 29
-# CANADA   CENTRAL    6 H  BEHIND UTC    REGINA, WINNIPEG
-# CANADA   CENTRAL    5 H  BEHIND UTC    APR 3 - OCT 29
-# CANADA   MOUNTAIN   7 H  BEHIND UTC    CALGARY, EDMONTON
-# CANADA   MOUNTAIN   6 H  BEHIND UTC    APR 3 - OCT 29
-# CANADA   PACIFIC    8 H  BEHIND UTC    VANCOUVER
-# CANADA   PACIFIC    7 H  BEHIND UTC    APR 3 - OCT 29
-# CANADA   YUKON      SAME AS PACIFIC    DAWSON
-
-# From Arthur David Olson (January 21, 1989):
-# April 3 fell on a Sunday in 1988; October 29 fell on a Sunday in 1989.  Ahem.
-# Note claim that there's double DST in Newfoundland and that Yukon should
-# be same as Pacific.
-
-# From W. Jones (jones@skdad.usask.ca) (November 6, 1992):
-# 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.
-#
-# Here's how I would summarize things.  Establish a "Saskatchewan" CST
-# time zone, and note that it officially exists as of 15 April 1966.  Any
-# current exceptions can put themselves in the "Mountain" zone, since
-# those are the rules they follow.  Any past exceptions can be forgotten,
-# since that's what those who live here have done.
-
-# From Arthur David Olson (November 21, 1992):
-# East-Saskatchewan kept to avoid problems for folks using that zone by name;
-# plain Saskatchewan added.
-
 # 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....
@@ -569,11 +513,22 @@ Link	Pacific/Honolulu	HST
 # 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).
 
 
-# From Shanks (1991):
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	StJohns	1884	only	-	Jan	 1	0:00	0	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
+
+# 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
@@ -611,8 +566,17 @@ Zone America/St_Johns	-3:30:52 -	LMT	1884
 			-3:31	StJohns	N%sT	1935 Mar 30
 			-3:30	StJohns	N%sT
 
+
+# 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	1902	only	-	Jun	15	0:00	0	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
@@ -656,9 +620,23 @@ 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	1884	only	-	Jan	 1	0:00	0	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
@@ -690,9 +668,20 @@ 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	1887	only	-	Jul	16	0:00	0	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
@@ -720,8 +709,41 @@ Rule	Winn	1987	max	-	Apr	Sun>=1	2:00	1:00	D
 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> (November 6, 1992):
+# 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	1905	only	-	Sep	 1	0:00	0	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
@@ -732,17 +754,31 @@ 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	14	2:00	1:00	D
-Rule	Regina	1946	only	-	Oct	13	2:00	0	S
-Rule	Regina	1947	1960	-	Apr	lastSun	2:00	1:00	D
-Rule	Regina	1947	1959	-	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	1966 Apr 15
+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	1906	only	-	Sep	 1	0:00	0	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
@@ -764,8 +800,14 @@ Rule	Edm	1987	max	-	Apr	Sun>=1	2:00	1:00	D
 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	1884	only	-	Jan	 1	0:00	0	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
@@ -778,24 +820,50 @@ 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 (1996-06-12):
+# 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.
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Yukon	1900	only	-	Jan	 1	0:00	0	S
-Rule	Yukon	1918	only	-	Apr	14	2:00	1:00	D
-Rule	Yukon	1918	only	-	Oct	27	2:00	0	S
-Rule	Yukon	1919	only	-	May	25	2:00	1:00	D
-Rule	Yukon	1919	only	-	Nov	 1	0:00	0	S
-Rule	Yukon	1942	only	-	Feb	 9	2:00	1:00	D
-Rule	Yukon	1965	only	-	Apr	25	0:00	1:00	D
-Rule	Yukon	1965	only	-	Oct	31	2:00	0	S
-Rule	Yukon	1980	1986	-	Apr	lastSun	2:00	1:00	D
-Rule	Yukon	1980	max	-	Oct	lastSun	2:00	0	S
-Rule	Yukon	1987	max	-	Apr	Sun>=1	2:00	1:00	D
+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
+#							0:00 ??
+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	Yukon	Y%sT	1966 Jul
-			-8:00	Yukon	P%sT
-# Parts of Yukon (e.g. Dawson) didn't switch to -8:00 until 1973 Oct 28.
+			-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 lastSun 2:00
+			-8:00	NT_YK	P%sT
+
 
 ###############################################################################
 
@@ -848,22 +916,45 @@ Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
 # 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> (November 18, 1993):
+# 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 Paul Eggert (1996-02-07):
-# Today in news:4f90v4$g6g@news.internet.com.mx, Kevin Pitts
-# <bravo2@internet.com.mx> wrote that Mexico will use Horario de Verano (DST)
-# starting this year with the same rules as the US, and gave FIDE as a source.
-# (FIDE is a private organization that promotes efficient electrical use.)
-# On 1996-02-02 Mario Camou wrote that the transition times are Apr Sun>=1
-# 0:00 and Nov 1 0:00 but also wrote ``The DST-out date looks a bit fishy''.
-# Go with Pitts after 1996, and with Shanks before that.
+# 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	1922	only	-	Jan	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
@@ -930,7 +1021,6 @@ Zone	America/Antigua	-4:07:12 -	LMT	1912 Mar 2
 
 # Bahamas
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Bahamas	1912	only	-	Mar	2	0:00	0	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
@@ -940,7 +1030,6 @@ Zone	America/Nassau	-5:09:24 -	LMT	1912 Mar 2
 
 # Barbados
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Barb	1932	only	-	Jan	1	0:00	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
@@ -954,7 +1043,6 @@ Zone America/Barbados	-3:58:28 -	LMT	1924		# Bridgetown
 # Belize
 # Whitman entirely disagrees with Shanks; go with Shanks.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Belize	1912	only	-	Apr	 1	0:00	0	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
@@ -984,7 +1072,6 @@ Zone	America/Cayman	-5:25:32 -	LMT	1890		# Georgetown
 # 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	1921	only	-	Jan	15	0:00	0	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	only	-	Jan	19	0:00	1:00	D
@@ -1010,7 +1097,6 @@ Zone America/Costa_Rica	-5:36:20 -	LMT	1890		# San Jose
 
 # From Shanks (1991):
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Cuba	1925	only	-	Jul	19	12:00	0	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
@@ -1049,7 +1135,6 @@ Zone America/Dominica	-4:05:36 -	LMT	1911 Jul 1 0:01		# Roseau
 
 # Dominican Republic
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	DR	1933	only	-	Apr	1	12:00	0	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
@@ -1064,7 +1149,6 @@ Zone America/Santo_Domingo -4:39:36 -	LMT	1890
 
 # El Salvador
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Salv	1921	only	-	Jan	1	0:00	0	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'.
@@ -1084,7 +1168,6 @@ Zone America/Guadeloupe	-4:06:08 -	LMT	1911 Jun 8	# Pointe a Pitre
 
 # Guatemala
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Guat	1918	only	-	Oct	5	0:00	0	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
@@ -1095,7 +1178,6 @@ Zone America/Guatemala	-6:02:04 -	LMT	1918 Oct 5
 
 # Haiti
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Haiti	1917	only	-	Jan	24	12:00	0	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
@@ -1142,7 +1224,6 @@ Zone America/Montserrat	-4:08:52 -	LMT	1911 Jul 1 0:01   # Plymouth
 
 # Nicaragua
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	Nic	1975	only	-	Feb	16	0:00	0	S
 Rule	Nic	1979	1980	-	Mar	Sun>=16	0:00	1:00	D
 Rule	Nic	1979	1980	-	Jun	Mon>=23	0:00	0	S
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]