# Texas timezone history
# compiled by Jules Descartes September 2011
# published under Creative Commons license 
# http://creativecommons.org/licenses/by/3.0/deed.en

# Sources:
# Doris Chase Doane, Time changes in the USA (quoted as DCD)
# Thomas Shanks, American Atlas, various editions (quoted as Shanks)
# Newspaper archives accessible via Internet
# 

# visual map posted to Wikimedia
# http://commons.wikimedia.org/wiki/File:Texas_timezones.jpg
# 

# We propose three zone files
# For the first of them, the standard tzdata definitions are fine

# Far western Texas (El Paso County, Hudspeth County,
# and Pine Springs and Nickel Creek in Culberson County)
# has MST since 1883
Link	America/Denver	America/El_Paso

# The main part of Texas has always CST. Contrary to what tzdata file
# northamerica claims, it is not like America/Chicago, as it had not DST in
# 1936. We name it after the most populous city Houston at 95w22
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Houston	-6:21:28 -	LMT	1883 Nov 18 11:38:32
			-6:00	US	C%sT	

# The 'Panhandle and Plains' section of Texas has CST, but had a two year
# period of MST between 1919 and 1921. A posting to the tzdata-history mailing
# list provides original documents:
# http://groups.google.com/group/tzdata-history/browse_thread/thread/5e0d0d24ba438e4c
# In short: A US goverment decision in March 1918 announced a change in time
# zone boundaries. The CST/MST boundary was to run through Texas roughly along
# the meridian 100w, with a bulge to the west around the towns of Sweatwater,
# Big Springs and San Angelo, stating 1919 Jan 1 at 02 am. The local Panhandle
# and Plains chamber of commerce was not happy in 1919 to be in another time
# zone than the more populated south-east of the state, and they petitioned a
# change.
# A US congress decision of 1921 March 4 became part of the Unit States Code
# as section 265 and movs the Panhandle and Plain area back to CST. For the
# data, we follow Shanks the change date of 1921 Mar 27. We assume that the
# 1919 DST was observed like in the rest of the US.
#
# The zone is named after the largest town in the panhandle Amarillo, 101w50.
# Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
Zone America/Amarillo	-6:47:20 -	LMT	1883 Nov 18 11:12:40
			-6:00	US	C%sT	1919 Jan 1  02:00
			-7:00	US	M%sT	1921 Mar 7  02:00
			-6:00	US	C%sT