proposed tz patches for Mexico, Nunavut, Vostok, etc.

Paul Eggert eggert at twinsun.com
Sun Apr 1 10:37:56 UTC 2001


Jesper Norgaard's letter about what actually happened in Mexico this
morning prompted me to propose the tz patches enclosed below, which
accumulate most of the changes recently proposed.  The patches for
Mexico are the most important, though Nunavut and Vostok also need
fixes now so that current time stamps are reported correctly.

Sorry, I haven't had time to think through the issue of Australian
time zone abbreviations yet.  If I recall correctly, we have so far:

  * one well-researched proposal to change from EST/EST etc to AEST/AEDT etc; 
  * one second.
  * one dissenting vote to leave it at is.
  * my own brief research indicating that Australians themselves are
     not consistent

Right now we have to get the Mexican patches out, so I'll leave the
Australian abbreviations alone for now, but I'd like more votes and/or
research if possible.



Anyway, here is a summary of the patch proposed below:

* Despite earlier predictions, America/Monterrey and America/Chihuahua did
  _not_ change their clocks today.  They will change at the same time as
  the rest of Mexico.  (Thanks to Jesper Norgaard for this.)

* Nunavut went back to its pre-1999 ways, effective today.  (Thanks to
  Rives McDow for this.)

* Antarctica/Vostok is at UTC+6, not UTC+3.  The message I got from
  Vostok was a bit confusing; perhaps nobody in Antarctica observes
  DST, contrary to our tables?  We need more info about this.  (Thanks
  to Lee Hotz for this.)

* Correct several errors for Dutch daylight saving time before World
  War II.  (Thanks to Robert H. van Gent for this.)

* Alaska switched from Asian to American dates on 1867-10-18.  We can't
  capture the Julian-to-Gregorian switch that occurred at the same time,
  but at least we can capture the 24-hour time zone change.
  (Thanks to Robert H. van Gent for this.)

* The Philippines switched from American to Asian dates on 1844-12-31.
  (Thanks to Robert H. van Gent for obtaining a copy of the
  proclamation.)  For now, guess the Ladrones switched at the same
  time.


The following changes affect commentary only:

* Add references to Vzic (a tz-to-VTIMEZONE compiler), and to
  possible XML schemata for tz data.

* Add references to a history of the International Date Line, and to
  Netherlands time zone history.  (Thanks to Robert H. van Gent for
  this.)

* Update the status of various Antarctic stations, some of which have
  closed.

* Update the instructions for running the XHTML validator.


===================================================================
RCS file: RCS/antarctica,v
retrieving revision 2001.1
retrieving revision 2001.1.0.2
diff -pu -r2001.1 -r2001.1.0.2
--- antarctica	2001/03/13 17:57:38	2001.1
+++ antarctica	2001/04/01 10:15:23	2001.1.0.2
@@ -200,25 +200,27 @@ Rule	NZAQ	1990	max	-	Mar	Sun>=15	2:00s	0
 # Russia - year-round bases
 # Bellingshausen, King George Island, -621159-0585337, since 1968-02-22
 # Mirny, Davis coast, -6633+09301, since 1956-02
-# Molodezhnaya
-# Novolazarevskaya
+# Molodezhnaya, Alasheyev Bay, year-round from 1962-02 to 1999-07-01
+# Novolazarevskaya, Queen Maud Land, -7046+01150,
+#	year-round from 1960/61 to 1992
 
-# Vostok, since 1957-12-16
+# Vostok, since 1957-12-16, temporarily closed 1994-02/1994-11
 # <a href="http://quest.arc.nasa.gov/antarctica/QA/computers/Directions,Time,ZIP">
 # From Craig Mundell (1994-12-15)</a>:
 # Vostok, which is one of the Russian stations, is set on the same
 # time as Moscow, Russia.
 #
-# From Paul Eggert (2001-03-03):
-# Today I talked with a neighbor Robert Lee Hotz, a neighbor who
-# recently returned from Vostok.  He said that the Americans have a
-# substation next to Vostok that keeps New Zealand time.
-# He thought the Russians still use Moscow time, but wasn't sure.
+# From Lee Hotz (2001-03-08):
+# I queried the folks at Columbia who spent the summer at Vostok and this is
+# what they had to say about time there:
+# ``in the US Camp (East Camp) we have been on New Zealand (McMurdo)
+# time, which is 12 hours ahead of GMT. The Russian Station Vostok was
+# 6 hours behind that (although only 2 miles away, i.e. 6 hours ahead
+# of GMT). This is a time zone I think two hours east of Moscow. The
+# natural time zone is in between the two: 8 hours ahead of GMT.''
 #
 Zone Antarctica/Vostok	0	-	zzz	1957 Dec 16
-			3:00	RussAQ	MSK/MSD	1991 Mar 31 2:00s
-			2:00	RussAQ	EE%sT	1992 Jan 19 2:00s
-			3:00	RussAQ	MSK/MSD
+			6:00	-	VOST	# Vostok time
 
 # S Africa - year-round bases
 # Marion Island
@@ -231,14 +233,16 @@ Zone Antarctica/Vostok	0	-	zzz	1957 Dec 
 #	scientific station from 1903
 #	whaling station at Signy I 1920/1926
 # South Shetland Islands
-#	whaling station at Deception I 1912/1931
-#	scientific station from 1943;
-#	previously sealers and a scientific expedition wintered by accident,
-#	and a garrison was deployed briefly
 #
 # year-round bases
 # Bird Island, South Georgia, -5400-03803, since 1983
-# Halley, Coates Land, -7535-2619, since 1956-01-06
+# Deception Island, -6259-06034, whaling station 1912/1931,
+#	scientific station 1943/1967,
+#	previously sealers and a scientific expedition wintered by accident,
+#	and a garrison was deployed briefly
+# Halley, Coates Land, -7535-02604, since 1956-01-06
+#	Halley is on a moving ice shelf and is periodically relocated
+#	so that it is never more than 10km from its nominal location.
 # Rothera, Adelaide Island, -6734-6808, since 1976-12-01
 
 # Uruguay - year round base
@@ -262,12 +266,13 @@ Zone Antarctica/Palmer	0	-	zzz	1965
 			-4:00	ChileAQ	CL%sT
 #
 #
-# McMurdo, Ross Island, since 1956
+# McMurdo, Ross Island, since 1955-12
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Antarctica/McMurdo	0	-	zzz	1956
 			12:00	NZAQ	NZ%sT
 #
-# Amundsen-Scott, South Pole, since 1957-01-23
+# Amundsen-Scott, South Pole, continuously occupied since 1956-11-20
+#
 # From Paul Eggert (1996-09-03):
 # Normally it wouldn't have a separate entry, since it's like the
 # larger Antarctica/McMurdo since 1970, but it's too famous to omit.
===================================================================
RCS file: RCS/asia,v
retrieving revision 2001.1
retrieving revision 2001.1.0.1
diff -pu -r2001.1 -r2001.1.0.1
--- asia	2001/03/13 17:57:38	2001.1
+++ asia	2001/04/01 10:08:58	2001.1.0.1
@@ -1111,7 +1111,10 @@ Zone	Asia/Gaza	2:17:52	-	LMT	1900 Oct
 # no information
 
 # Philippines
-# Howse writes (p 153) that until 1844 the Philippines kept American date.
+# On 1844-08-16, Narciso Claveria, governor-general of the
+# Philippines, issued a proclamation announcing that 1844-12-30 was to
+# be immediately followed by 1845-01-01.  Robert H. van Gent has a
+# transcript of the decree in <http://www.phys.uu.nl/~vgent/idl/idl.htm>.
 # The rest of this data is from Shanks.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Phil	1936	only	-	Nov	1	0:00	1:00	S
@@ -1121,7 +1124,7 @@ Rule	Phil	1954	only	-	Jul	1	0:00	0	-
 Rule	Phil	1978	only	-	Mar	22	0:00	1:00	S
 Rule	Phil	1978	only	-	Sep	21	0:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone	Asia/Manila	-15:56:00 -	LMT	1844
+Zone	Asia/Manila	-15:56:00 -	LMT	1844 Dec 31
 			8:04:00 -	LMT	1899 May 11
 			8:00	Phil	PH%sT	1942 May
 			9:00	-	JST	1944 Nov
===================================================================
RCS file: RCS/australasia,v
retrieving revision 2001.1
retrieving revision 2001.1.0.1
diff -pu -r2001.1 -r2001.1.0.1
--- australasia	2001/03/13 17:57:39	2001.1
+++ australasia	2001/04/01 10:08:58	2001.1.0.1
@@ -222,7 +222,8 @@ Zone	Pacific/Tahiti	 -9:58:16 -	LMT	1912
 
 # Guam
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone	Pacific/Guam	 9:39:00 -	LMT	1901		# Agana
+Zone	Pacific/Guam	-14:21:00 -	LMT	1844 Dec 31
+			 9:39:00 -	LMT	1901		# Agana
 			10:00	-	GST	2000 Dec 23	# Guam
 			10:00	-	ChST	# Chamorro Standard Time
 
@@ -241,7 +242,8 @@ Zone Pacific/Kiritimati	-10:29:20 -	LMT	
 
 # N Mariana Is
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone Pacific/Saipan	 9:43:00 -	LMT	1901
+Zone Pacific/Saipan	-14:17:00 -	LMT	1844 Dec 31
+			 9:43:00 -	LMT	1901
 			 9:00	-	MPT	1969 Oct # N Mariana Is Time
 			10:00	-	MPT	2000 Dec 23
 			10:00	-	ChST	# Chamorro Standard Time
@@ -977,7 +979,8 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # Howse writes (p 153) ``The Spaniards, on the other hand, reached the
 # Philippines and the Ladrones from America,'' and implies that the Ladrones
 # (now called the Marianas) kept American date for quite some time.
-# Ignore this for now, as we have no hard data.  See also Asia/Manila.
+# For now, we assume the Ladrones switched at the same time as the Philippines;
+# see Asia/Manila.
 
 # US Public Law 106-564 (2000-12-23) made UTC+10 the official standard time,
 # under the name "Chamorro Standard Time".  There is no official abbreviation,
===================================================================
RCS file: RCS/europe,v
retrieving revision 2001.1
retrieving revision 2001.1.0.1
diff -pu -r2001.1 -r2001.1.0.1
--- europe	2001/03/13 17:57:39	2001.1
+++ europe	2001/04/01 10:08:58	2001.1.0.1
@@ -405,6 +405,11 @@ Rule	EU	1978	only	-	Oct	 1	 1:00u	0	-
 Rule	EU	1979	1995	-	Sep	lastSun	 1:00u	0	-
 Rule	EU	1981	max	-	Mar	lastSun	 1:00u	1:00	S
 Rule	EU	1996	max	-	Oct	lastSun	 1:00u	0	-
+# The most recent directive covers the years starting in 2002.  See:
+# <a href="http://europa.eu.int/eur-lex/en/lif/dat/2000/en_300L0084.html"
+# Directive 2000/84/EC of the European Parliament and of the Council
+# of 19 January 2001 on summer-time arrangements.
+# </a>
 
 # W-Eur differs from EU only in that W-Eur uses standard time.
 Rule	W-Eur	1977	1980	-	Apr	Sun>=1	 1:00s	1:00	S
@@ -1368,37 +1373,33 @@ Zone	Europe/Monaco	0:29:32 -	LMT	1891 Ma
 # Netherlands
 # Howse writes that the Netherlands' railways used GMT between 1892 and 1940,
 # but for other purposes the Netherlands used Amsterdam mean time.
+# The data before 1945 is taken from
+# <http://www.phys.uu.nl/~vgent/wettijd/wettijd.htm>.
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-# Shanks gives 1916 Apr 30 24:00 and 1916 Oct 1 00:00; go with Whitman.
-Rule	Neth	1916	only	-	May	 1	2:00s	1:00	NST	# Netherlands Summer Time
-Rule	Neth	1916	only	-	Oct	 2	2:00s	0	AMT	# Amsterdam Mean Time
+Rule	Neth	1916	only	-	May	 1	0:00	1:00	NST	# Netherlands Summer Time
+Rule	Neth	1916	only	-	Oct	 1	0:00	0	AMT	# Amsterdam Mean Time
 Rule	Neth	1917	only	-	Apr	16	2:00s	1:00	NST
 Rule	Neth	1917	only	-	Sep	17	2:00s	0	AMT
-# Whitman gives 1918 Apr 14, 1918 Oct 31, and 1921 Sep 28; go with Shanks.
 Rule	Neth	1918	1921	-	Apr	Mon>=1	2:00s	1:00	NST
-Rule	Neth	1918	1921	-	Sep	Mon>=24	2:00s	0	AMT
-Rule	Neth	1922	only	-	Mar	26	2:00s	1:00	NST
-# Whitman gives 1939 Oct 1; go with Shanks.
+Rule	Neth	1918	1921	-	Sep	lastSun	2:00s	0	AMT
+Rule	Neth	1922	only	-	Mar	lastSun	2:00s	1:00	NST
 Rule	Neth	1922	1936	-	Oct	Sun>=2	2:00s	0	AMT
-Rule	Neth	1923	only	-	Jun	 1	2:00s	1:00	NST
-Rule	Neth	1924	only	-	Mar	30	2:00s	1:00	NST
-# Whitman gives 1925 Apr 5; go with Shanks.
-Rule	Neth	1925	only	-	Jun	 5	2:00s	1:00	NST
-# For 1926 through 1930 Whitman gives Apr 15; go with Shanks.
+Rule	Neth	1923	only	-	Jun	Fri>=1	2:00s	1:00	NST
+Rule	Neth	1924	only	-	Mar	lastSun	2:00s	1:00	NST
+Rule	Neth	1925	only	-	Jun	Fri>=1	2:00s	1:00	NST
 Rule	Neth	1926	1931	-	May	15	2:00s	1:00	NST
 Rule	Neth	1932	only	-	May	22	2:00s	1:00	NST
 Rule	Neth	1933	1936	-	May	15	2:00s	1:00	NST
 Rule	Neth	1937	only	-	May	22	2:00s	1:00	NST
 Rule	Neth	1937	only	-	Jul	 1	0:00	1:00	S
 Rule	Neth	1937	1939	-	Oct	Sun>=2	2:00s	0	-
-# Whitman gives 1939 Apr 15 and 1940 Apr 19; go with Shanks.
 Rule	Neth	1938	1939	-	May	15	2:00s	1:00	S
 Rule	Neth	1945	only	-	Apr	 2	2:00s	1:00	S
-Rule	Neth	1945	only	-	May	20	2:00s	0	-
+Rule	Neth	1945	only	-	Sep	16	2:00s	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Europe/Amsterdam	0:19:28 -	LMT	1892 May
 			0:19:28	Neth	%s	1937 Jul
-			0:20	Neth	NE%sT	1940 May 16 0:40
+			0:20	Neth	NE%sT	1940 May 17 0:00
 			1:00	C-Eur	CE%sT	1945 Apr  2 2:00
 			1:00	Neth	CE%sT	1977
 			1:00	EU	CE%sT
===================================================================
RCS file: RCS/Makefile,v
retrieving revision 2000.8
retrieving revision 2000.8.0.1
diff -pu -r2000.8 -r2000.8.0.1
--- Makefile	2000/12/14 20:33:20	2000.8
+++ Makefile	2001/04/01 10:08:58	2000.8.0.1
@@ -218,11 +218,22 @@ ZIC=		$(zic) $(ZFLAGS)
 # The name of a Posix-compliant `awk' on your system.
 AWK=		nawk
 
-# The name and arguments of a program to validate your web pages.
+# The path where SGML DTDs are kept.
+SGML_SEARCH_PATH= $(TOPDIR)/share/doc/sgml-lib/REC-xhtml1-20000126/
+
+# The catalog file(s) to use when validating XHTML.
+SGML_CATALOG_FILES= xhtml.soc
+
+# The name, arguments and environment of a program to validate your web pages.
 # See <http://www.jclark.com/sp/> for a validator, and
 # <http://validator.w3.org/source/> for a validation library.
 VALIDATE = nsgmls
-VALIDATEFLAGS = -s -B -wall -wno-unused-param
+VALIDATE_FLAGS = -s -B -wall -wno-unused-param -wxml
+VALIDATE_ENV = \
+  SGML_CATALOG_FILES=$(SGML_CATALOG_FILES) \
+  SGML_SEARCH_PATH=$(SGML_SEARCH_PATH) \
+  SP_CHARSET_FIXED=YES \
+  SP_ENCODING=UTF-8
 
 ###############################################################################
 
@@ -357,7 +368,7 @@ check_tables:	checktab.awk $(PRIMARY_YDA
 		$(AWK) -f checktab.awk $(PRIMARY_YDATA)
 
 check_web:	$(WEB_PAGES)
-		$(VALIDATE) $(VALIDATEFLAGS) $(WEB_PAGES)
+		$(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) $(WEB_PAGES)
 
 clean:
 		rm -f core *.o *.out tzselect zdump zic yearistype date \
===================================================================
RCS file: RCS/northamerica,v
retrieving revision 2001.1
retrieving revision 2001.1.0.1
diff -pu -r2001.1 -r2001.1.0.1
--- northamerica	2001/03/13 17:57:40	2001.1
+++ northamerica	2001/04/01 10:08:58	2001.1.0.1
@@ -280,40 +280,47 @@ Zone America/Los_Angeles -7:52:58 -	LMT	
 # Alaska
 # AK%sT is the modern abbreviation for -9:00 per USNO.
 #
-# From Paul Eggert (1995-12-19):
+# From Paul Eggert (2001-04-01):
 # 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.
+# This was on 1867-10-18, a Friday; the previous day was 1867-10-06 Julian,
+# also a Friday.  Include only the time zone part of this transition,
+# ignoring the switch from Julian to Gregorian, since we can't represent
+# the Julian calendar.
 #
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-Zone America/Juneau	 -8:57:41 -	LMT	1900 Aug 20 12:00
+Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 18
+			 -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
+Zone America/Yakutat	 14:41:05 -	LMT	1867 Oct 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 Oct 30 2:00
 			 -9:00	US	AK%sT
-Zone America/Anchorage	 -9:59:36 -	LMT	1900 Aug 20 12:00
+Zone America/Anchorage	 14:00:24 -	LMT	1867 Oct 18
+			 -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
+Zone America/Nome	 12:58:21 -	LMT	1867 Oct 18
+			-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
+Zone America/Adak	 12:13:21 -	LMT	1867 Oct 18
+			-11:46:38 -	LMT	1900 Aug 20 12:00
 			-11:00	-	NST	1942
 			-11:00	US	N%sT	1946
 			-11:00	-	NST	1967 Apr
@@ -1138,6 +1145,16 @@ Zone America/Dawson_Creek -8:00:56 -	LMT
 # 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).]
+
 # 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
@@ -1155,19 +1172,21 @@ Zone America/Pangnirtung -4:22:56 -	LMT	
 			-4:00	NT_YK	A%sT	1995 Apr Sun>=1 2:00
 			-5:00	Canada	E%sT	1999 Oct 31 2:00
 			-6:00	Canada	C%sT	2000 Oct 29 2:00
-			-5:00	-	EST
+			-5:00	Canada	E%sT
 Zone America/Iqaluit	-4:33:52 -	LMT	1884 # Frobisher Bay before 1987
 			-5:00	NT_YK	E%sT	1999 Oct 31 2:00
 			-6:00	Canada	C%sT	2000 Oct 29 2:00
-			-5:00	-	EST
+			-5:00	Canada	E%sT
 Zone America/Rankin_Inlet -6:08:40 -	LMT	1884
 			-6:00	NT_YK	C%sT	2000 Oct 29 2:00
-			-5:00	-	EST
+			-5:00	-	EST	2001 Apr  1 3:00
+			-6:00	Canada	C%sT
 Zone America/Cambridge_Bay -7:00:20 -	LMT	1884
 			-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	Canada	C%sT
+			-6:00	-	CST	2001 Apr  1 3:00
+			-7:00	Canada	M%sT
 Zone America/Yellowknife -7:37:24 -	LMT	1884
 			-7:00	NT_YK	M%sT
 Zone America/Inuvik	-8:54:00 -	LMT	1884
@@ -1294,16 +1313,25 @@ Zone America/Dawson	-9:17:40 -	LMT	1900 
 # James F. Smith writes in today's LA Times
 # </a>
 # * Sonora will continue to observe standard time.
-# * Border states including Baja California, Chihuahua, and Nuevo Leon
-#   will use US rules,
 # * Last week Mexico City's mayor Andres Manuel Lopez 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
-# and that border states and Durango will stick with US rules.
+# For now we'll assume that the Federal District will bow to federal rules.
+
+# From Jesper Norgaard (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" <www.diariodemonterrey.com/index.asp>
+# Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2000-03-31)
 
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Mexico	1939	only	-	Feb	5	0:00	1:00	D
@@ -1333,8 +1361,7 @@ Zone America/Merida	-5:58:28 -	LMT	1922 
 Zone America/Monterrey	-6:41:16 -	LMT	1921 Dec 31 23:18:44
 			-6:00	-	CST	1988
 			-6:00	US	C%sT	1989
-			-6:00	Mexico	C%sT	2001
-			-6:00	US	C%sT
+			-6:00	Mexico	C%sT
 # Central Mexico
 Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  0:23:24
 			-7:00	-	MST	1927 Jun 10 23:00
@@ -1353,8 +1380,7 @@ Zone America/Chihuahua	-7:04:20 -	LMT	19
 			-6:00	-	CST	1996
 			-6:00	Mexico	C%sT	1998
 			-6:00	-	CST	1998 Apr Sun>=1 3:00
-			-7:00	Mexico	M%sT	2001
-			-7:00	US	M%sT
+			-7:00	Mexico	M%sT
 # Sonora
 Zone America/Hermosillo	-7:23:52 -	LMT	1921 Dec 31 23:36:08
 			-7:00	-	MST	1927 Jun 10 23:00
===================================================================
RCS file: RCS/tz-link.htm,v
retrieving revision 2001.1
retrieving revision 2001.1.0.1
diff -pu -r2001.1 -r2001.1.0.1
--- tz-link.htm	2001/03/13 17:57:44	2001.1
+++ tz-link.htm	2001/04/01 10:08:58	2001.1.0.1
@@ -51,9 +51,10 @@ the code is in the file <samp>tzcode<var
 where <samp><var>C</var></samp> is the code's version;
 similarly, the data are in <samp>tzdata<var>D</var>.tar.gz</samp>,
 where <samp><var>D</var></samp> is the data's version.
-The code lets you compile the text data into time zone files, one for
-each location.  It also lets you read a compiled time zone file and
-interpret time stamps for that location.</p>
+The code lets you compile the <samp>tz</samp> source files into
+machine-readable binary files, one for each location.  It also lets
+you read a <samp>tz</samp> binary file and interpret time stamps for that
+location.</p>
 <p>
 The data are by no means authoritative. If you find errors, please
 send changes to the <a href="mailto:tz at elsie.nci.nih.gov">time zone
@@ -92,17 +93,36 @@ holidays.</li>
 is a web interface to a time zone database derived from
 <samp>tz</samp>'s.</li>
 </ul>
-<h2>Other time zone file readers</h2>
+<h2>Other <samp>tz</samp> compilers</h2>
+<ul>
+<li><a href="http://www.karuna.freeserve.co.uk/vzic.tgz">Vzic</a>
+compiles <samp>tz</samp> source into VTIMEZONE text as specified by
+the <a href="ftp://ftp.isi.edu/in-notes/rfc2445.txt">iCalendar</a>
+specification published by the <a
+href="http://www.ietf.org/html.charters/calsch-charter.html">IETF
+Calendaring and Scheduling Working Group</a>. Vzic is freely
+available under the <a href="http://www.gnu.org/copyleft/gpl.html">GNU
+General Public License (GPL)</a>.</li>
+<li>Possible XML schemata for the <samp>tz</samp> data include <a
+href="http://www.w3.org/2000/01/foo">one</a> sketched out by <a
+href="http://www.w3.org/People/Berners-Lee/">Tim Berners-Lee</a> and
+<a
+href="http://developer.iplanet.com/docs/wpapers/calendar/ietf.txt">another</a>
+used by the <a
+href="http://www.iplanet.com/products/iplanet_calendar/">iPlanet
+Calendar Server</a>.</li>
+</ul>
+<h2>Other <samp>tz</samp> binary file readers</h2>
 <ul>
 <li>The <a href="http://www.gnu.org/software/libc/">GNU C Library</a>
 has an independent, thread-safe implementation of
-a time zone file reader that is compatible with <samp>tz</samp>.
+a <samp>tz</samp> binary file reader.
 This library is freely available under the
 <a href="http://www.gnu.org/copyleft/lesser.html">
 GNU Lesser General Public License (LGPL)</a>,
 and is widely used in GNU/Linux systems.</li>
 <li><a href="http://www.bmsi.com/java/#TZ">ZoneInfo.java</a>
-is a time zone file reader written in Java.
+is a <samp>tz</samp> binary file reader written in Java.
 It is freely available under the GNU LGPL.</li>
 </ul>
 <h2>Other <samp>tz</samp>-based time zone conversion software</h2>
@@ -164,9 +184,7 @@ currently observes a different time.</li
 <li>Manifold.net's <a
 href="http://www.manifold.net/download/freemaps.html">Free Maps and
 GIS Data</a> includes a Manifold-format map of world time zone
-boundaries distributed under the <a
-href="http://www.gnu.org/copyleft/gpl.html">GNU General Public License
-(GPL)</a>. The GeoCommunity's <a
+boundaries distributed under the GPL. The GeoCommunity's <a
 href="http://software.geocomm.com/data/intl_timezones.html">International
 Time Zones</a> publishes the same data in other formats.</li>
 <li>The US Geological Survey's National Atlas of the United States
@@ -186,6 +204,9 @@ Time of Internet</a>
 contains good descriptions of Time Zones and daylight saving time,
 with diagrams.
 The time zone map is out of date, however.</li>
+<li><a href="http://www.phys.uu.nl/~vgent/idl/idl.htm">A History of
+the International Date Line</a> tells the story of the most important
+time zone boundary.</li>
 <li>A few countries have well-documented histories of legal time.
 <dl>
 <dt>Australia</dt>
@@ -211,6 +232,10 @@ hreflang="he">announcements (in Hebrew)<
 Congress has published a <a
 href="http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/"
 hreflang="es">history of Mexican local time (in Spanish)</a>.</dd>
+<dt>Netherlands</dt>
+<dd><a href="http://www.phys.uu.nl/~vgent/wettijd/wettijd.htm"
+hreflang="nl">De wettelijke tijdregeling in Nederland (in Dutch)</a>
+covers the history of local time in the Netherlands from ancient times.</dd>
 <dt>United Kingdom</dt>
 <dd><a
 href="http://student.cusu.cam.ac.uk/~jsm28/british-time/">History of



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