detroit_timezone.txt

# Source: https://www.iana.org/time-zones/repository/releases/tzdata2020c.tar.gz
#
# Michigan
#
# From Bob Devine (1988-01-28):
# Michigan didn't observe DST from 1968 to 1973.
#
# From Paul Eggert (1999-03-31):
# Shanks writes that Michigan started using standard time on 1885-09-18,
# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
# 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#	was rescinded and the city reverted to Sun time.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.
#
# From Paul Eggert (2001-03-06):
# Garland (1927) writes "Cleveland and Detroit advanced their clocks
# one hour in 1914."  This change is not in Shanks.  We have no more
# info, so omit this for now.
#
# From Paul Eggert (2019-07-06):
# Due to a complicated set of legal maneuvers, in 1967 Michigan did
# not start daylight saving time when the rest of the US did.
# Instead, it began DST on Jun 14 at 00:01.  This was big news:
# the Detroit Free Press reported it at the top of Page 1 on
# 1967-06-14, in an article "State Adjusting to Switch to Fast Time"
# by Gary Blonston, above an article about Thurgood Marshall's
# confirmation to the US Supreme Court.  Although Shanks says Detroit
# observed DST until 1967-10-29 00:01, that time of day seems to be
# incorrect, as the Free Press later said DST ended in Michigan at the
# same time as the rest of the US.  Also, although Shanks reports no DST in
# Detroit in 1968, it did observe DST that year; in the November 1968
# election Michigan voters narrowly repealed DST, effective 1969.
#
# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
# Rule	NAME	FROM	TO	-	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
# Zone	NAME		STDOFF	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	1967 Jun 14  0:01
			-5:00	US	E%sT	1969
			-5:00	-	EST	1973
			-5:00	US	E%sT	1975
			-5:00	-	EST	1975 Apr 27  2:00
			-5:00	US	E%sT