FW: Daylight Savings Time in Mexico

Olson, Arthur David (NCI) olsona at dc37a.nci.nih.gov
Tue Apr 2 14:09:13 UTC 2002


Henry Ivy is not on the time zone mailing list; direct replies
appropriately.

				--ado

-----Original Message-----
From: IVY,HENRY (HP-Roseville,ex1) [mailto:henry_ivy at am.exch.hp.com]
Sent: Monday, April 01, 2002 9:15 PM
To: 'tz at elsie.nci.nih.gov'
Cc: VEGA,HORACIO (HP-Mexico,ex1); GRIMM,GREG (HP-Roseville,ex1)
Subject: Daylight Savings Time in Mexico


Dear Sirs;

I work for Hewlett-Packard in Roseville, CA, USA.  One of my assignments is
to 
maintain daylight savings time schedules in special databases for world wide
global
support.  I admire your work.  I look forward to any comments that you may
have
about the following information.

Horacio Vega works for HP in Mexico.  He brought the following decree
to my attention.  His Spanish is better than mine.  He has told me that
Mexico City
will use daylight savings time, along with most of Mexico.

http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html#decreto

I started with the tzdata2002b version of the data.

The rules for Mexico Daylight Savings Time should have the 2001 rules
commented out,
and the previous two lines reset to run to max.

The time zone rules for America/Mexico_City should have the last line
commented out,
and the previous line reset to not expire.

The time zone rules for America/Tijuana should have the last line commented
out,
and the previous line reset to not expire.


---------------

# 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	W
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	Mexico	2001	max	-	May	Sun>=1	2:00	1:00	D
# Rule	Mexico	2001	max	-	Sep	lastSun	2:00	0	S
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
# Quintana Roo
Zone America/Cancun	-5:47:04 -	LMT	1922 Jan  1  0:12:56
			-6:00	-	CST	1981 Dec 23
			-5:00	Mexico	E%sT	1998 Aug  2  2:00
			-6:00	Mexico	C%sT
# Campeche, Yucatan
Zone America/Merida	-5:58:28 -	LMT	1922 Jan  1  0:01:32
			-6:00	-	CST	1981 Dec 23
			-5:00	-	EST	1982 Dec  2
			-6:00	Mexico	C%sT
# Coahuila, Durango, Nuevo Leon, Tamaulipas
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
# Central Mexico
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 Apr  1
			-6:00	Mexico	C%sT
#			-6:00	-	CST
# Chihuahua
Zone America/Chihuahua	-7:04:20 -	LMT	1921 Dec 31 23:55:40
			-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 Apr  1
			-6:00	-	CST	1996
			-6:00	Mexico	C%sT	1998
			-6:00	-	CST	1998 Apr Sun>=1 3:00
			-7:00	Mexico	M%sT
# Sonora
Zone America/Hermosillo	-7:23:52 -	LMT	1921 Dec 31 23:36:08
			-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 Apr  1
			-6:00	-	CST	1942 Apr 24
			-7:00	-	MST	1949 Jan 14
			-8:00	-	PST	1970
			-7:00	Mexico	M%sT	1999
			-7:00	-	MST
# Baja California Sur, Nayarit, Sinaloa
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 Apr  1
			-6:00	-	CST	1942 Apr 24
			-7:00	-	MST	1949 Jan 14
			-8:00	-	PST	1970
			-7:00	Mexico	M%sT
# Baja California
Zone America/Tijuana	-7:48:04 -	LMT	1922 Jan  1  0:11:56
			-7:00	-	MST	1924
			-8:00	-	PST	1927 Jun 10 23:00
			-7:00	-	MST	1930 Nov 15
			-8:00	-	PST	1931 Apr  1
			-8:00	1:00	PDT	1931 Sep 30
			-8:00	-	PST	1942 Apr 24
			-8:00	1:00	PWT	1945 Nov 12
			-8:00	-	PST	1948 Apr  5
			-8:00	1:00	PDT	1949 Jan 14
			-8:00	-	PST	1954
			-8:00	CA	P%sT	1961
			-8:00	-	PST	1976
			-8:00	US	P%sT	1996
			-8:00	Mexico	P%sT
#			-8:00	US	P%sT

# From Paul Eggert (2001-03-05):
# Formerly there was an America/Ensenada zone, which differed from
# America/Tijuana only in that it did not observe DST from 1976
# through 1995.  This was as per Shanks.  However, Guy Harris reports
# that the 1987 OAG says "Only Ensenada, Mexicale, San Felipe and
# Tijuana observe DST," which contradicts Shanks but does imply that
# DST-observance was a town-by-town matter back then.  This concerns
# data after 1970 so most likely there should be at least one Zone
# other than America/Tijuana for Baja, but it's not clear yet what its
# name or contents should be.
#
# Revillagigedo Is
# no information

############################################################################
###
---------------

Regards, Hank Ivy

| Henry (Hank) B. Ivy           PHONE : (916)785-1392             |
|                               FAX   : (916)785-9238             |
| ecardfile : https://ecardfile.com/id/hank_ivy                   |
| Hewlett-Packard Company       USENET: hivy at rosemail.rose.hp.com |
| 8000 Foothills Boulevard, MS 5617                               |
| Roseville, California 95747-5617                                |
  



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