# tzdb data for North and Central America and environs
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# also includes Central America and the Caribbean
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (1999-03-22):
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
###############################################################################
# United States
# From Paul Eggert (1999-03-31):
# Howse writes (pp 121-125) that time zones were invented by
# Professor Charles Ferdinand Dowd (1825-1904),
# Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
# His pamphlet "A System of National Time for Railroads" (1870)
# was the result of his proposals at the Convention of Railroad Trunk Lines
# in New York City (1869-10). His 1870 proposal was based on Washington, DC,
# but in 1872-05 he moved the proposed origin to Greenwich.
# From Paul Eggert (2018-03-20):
# Dowd's proposal left many details unresolved, such as where to draw
# lines between time zones. The key individual who made time zones
# work in the US was William Frederick Allen - railway engineer,
# managing editor of the Travelers' Guide, and secretary of the
# General Time Convention, a railway standardization group. Allen
# spent months in dialogs with scientific and railway leaders,
# developed a workable plan to institute time zones, and presented it
# to the General Time Convention on 1883-04-11, saying that his plan
# meant "local time would be practically abolished" - a plus for
# railway scheduling. By the next convention on 1883-10-11 nearly all
# railroads had agreed and it took effect on 1883-11-18. That Sunday
# was called the "day of two noons", as some locations observed noon
# twice. Allen witnessed the transition in New York City, writing:
#
# I heard the bells of St. Paul's strike on the old time. Four
# minutes later, obedient to the electrical signal from the Naval
# Observatory ... the time-ball made its rapid descent, the chimes
# of old Trinity rang twelve measured strokes, and local time was
# abandoned, probably forever.
#
# Most of the US soon followed suit. See:
# Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
# https://dx.doi.org/10.2307/3105430
# From Paul Eggert (2005-04-16):
# That 1883 transition occurred at 12:00 new time, not at 12:00 old time.
# See p 46 of David Prerau, Seize the daylight, Thunder's Mouth Press (2005).
# From Paul Eggert (2006-03-22):
# A good source for time zone historical data in the US is
# Thomas G. Shanks, The American Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1991).
# Make sure you have the errata sheet; the book is somewhat useless without it.
# It is the source for most of the pre-1991 US entries below.
# From Paul Eggert (2001-03-06):
# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
# in his whimsical essay "An Economical Project for Diminishing the Cost
# of Light" published in the Journal de Paris (1784-04-26).
# 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,
# Clarke, Irwin (1947), XIX, Sunday
#
# For more about the first ten years of DST in the United States, see
# Robert Garland, Ten years of daylight saving from the Pittsburgh standpoint
# (Carnegie Library of Pittsburgh, 1927).
# https://web.archive.org/web/20160517155308/http://www.clpgh.org/exhibit/dst.html
#
# Shanks says that DST was called "War Time" in the US in 1918 and 1919.
# However, DST was imposed by the Standard Time Act of 1918, which
# was the first nationwide legal time standard, and apparently
# time was just called "Standard Time" or "Daylight Saving Time".
# From Paul Eggert (2019-06-04):
# Here is the legal basis for the US federal rules.
# * Public Law 65-106 (1918-03-19) implemented standard and daylight saving
# time for the first time across the US, springing forward on March's last
# Sunday and falling back on October's last Sunday.
# https://www.loc.gov/law/help/statutes-at-large/65th-congress/session-2/c65s2ch24.pdf
# * Public Law 66-40 (1919-08-20) repealed DST on October 1919's last Sunday.
# https://www.loc.gov/law/help/statutes-at-large/66th-congress/session-1/c66s1ch51.pdf
# * Public Law 77-403 (1942-01-20) started wartime DST on 1942-02-09.
# https://www.loc.gov/law/help/statutes-at-large/77th-congress/session-2/c77s2ch7.pdf
# * Public Law 79-187 (1945-09-25) ended wartime DST on 1945-09-30.
# https://www.loc.gov/law/help/statutes-at-large/79th-congress/session-1/c79s1ch388.pdf
# * Public Law 89-387 (1966-04-13) reinstituted a national standard for DST,
# from April's last Sunday to October's last Sunday, effective 1967.
# https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
# * Public Law 93-182 (1973-12-15) moved the 1974 spring-forward to 01-06.
# https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
# * Public Law 93-434 (1974-10-05) moved the 1975 spring-forward to
# February's last Sunday.
# https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
# * Public Law 99-359 (1986-07-08) moved the spring-forward to April's first
# Sunday.
# https://www.govinfo.gov/content/pkg/STATUTE-100/pdf/STATUTE-100-Pg764.pdf
# * Public Law 109-58 (2005-08-08), effective 2007, moved the spring-forward
# to March's second Sunday and the fall-back to November's first Sunday.
# https://www.govinfo.gov/content/pkg/PLAW-109publ58/pdf/PLAW-109publ58.pdf
# All transitions are at 02:00 local time.
# From Arthur David Olson:
# Before the Uniform Time Act of 1966 took effect in 1967, observance of
# Daylight Saving Time in the US was by local option, except during wartime.
# From Arthur David Olson (2000-09-25):
# Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
# In the introduction, Oboler spoke of "Eastern Peace Time."
# An AltaVista search turned up:
# https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
# "When the time is announced over the radio now, it is 'Eastern Peace
# Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."
# (August 1945) by way of confirmation.
#
# From Paul Eggert (2017-09-23):
# This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
# From Joseph Gallant citing
# George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
# At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
# to switch to London for Attlee's address, but the American people
# never got to hear his speech live. According to one press account,
# CBS' Bob Trout was first to announce the word of Japan's surrender,
# but a few seconds later, NBC, ABC and Mutual also flashed the word
# of surrender, all of whom interrupting the bells of Big Ben in
# London which were to precede Mr. Attlee's speech.
# From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout. From
# Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
#
# ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
# Any announcement from Asia would reach St. John's New York newsroom on a
# wire service teletype machine, which had prescribed signals for major news.
# Associated Press, for example, would ring five bells before spewing out
# typed copy of an important story, and 10 bells for news "of transcendental
# importance."
#
# On Aug. 14, stalling while talking steadily into the NBC networks' open
# microphone, St. John heard five bells and waited only to hear a sixth bell,
# before announcing confidently: "Ladies and gentlemen, World War II is over.
# The Japanese have agreed to our surrender terms."
#
# He had scored a 20-second scoop on other broadcasters.
# From Arthur David Olson (2005-08-22):
# Paul has been careful to use the "US" rules only in those locations
# that are part of the United States; this reflects the real scope of
# U.S. government action. So even though the "US" rules have changed
# in the latest release, other countries won't be affected.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
Rule US 1918 1919 - Oct lastSun 2:00 0 S
Rule US 1942 only - Feb 9 2:00 1:00 W # War
Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule US 1945 only - Sep 30 2:00 0 S
Rule US 1967 2006 - Oct lastSun 2:00 0 S
Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
Rule US 1974 only - Jan 6 2:00 1:00 D
Rule US 1975 only - Feb lastSun 2:00 1:00 D
Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
Rule US 1987 2006 - Apr Sun>=1 2:00 1:00 D
Rule US 2007 max - Mar Sun>=8 2:00 1:00 D
Rule US 2007 max - Nov Sun>=1 2:00 0 S
# From Arthur David Olson, 2005-12-19
# We generate the files specified below to guard against old files with
# obsolete information being left in the time zone binary directory.
# We limit the list to names that have appeared in previous versions of
# this time zone package.
# We do these as separate Zones rather than as Links to avoid problems if
# a particular place changes whether it observes DST.
# We put these specifications here in the northamerica file both to
# increase the chances that they'll actually get compiled and to
# avoid the need to duplicate the US rules in another file.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone EST -5:00 - EST
Zone MST -7:00 - MST
Zone HST -10:00 - HST
Zone EST5EDT -5:00 US E%sT
Zone CST6CDT -6:00 US C%sT
Zone MST7MDT -7:00 US M%sT
Zone PST8PDT -8:00 US P%sT
# From U. S. Naval Observatory (1989-01-19):
# USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
# USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
# USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
# USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
# USA MOUNTAIN 7 H BEHIND UTC DENVER
# USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
# USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
# USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
# USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
# USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
# USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
# USA " 9 H BEHIND UTC APR 3 - OCT 30
# USA HAWAII 10 H BEHIND UTC
# USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
# From Arthur David Olson (1989-01-21):
# The above dates are for 1988.
# Note the "AKST" and "AKDT" abbreviations, the claim that there's
# no DST in Samoa, and the claim that there is DST in Alaska and the
# Aleutians.
# From Arthur David Olson (1988-02-13):
# Legal standard time zone names, from United States Code (1982 Edition and
# Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
# up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
# took effect), as explained in sections 263 and 261:
# (none)
# United States standard eastern time
# United States standard mountain time
# United States standard central time
# United States standard Pacific time
# (none)
# United States standard Alaska time
# (none)
# Next, names from 1967-04-01 until 1983-11-30 (the date for
# public law 98-181):
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Yukon standard time
# Alaska-Hawaii standard time
# Bering standard time
# And after 1983-11-30:
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Alaska standard time
# Hawaii-Aleutian standard time
# Samoa standard time
# The law doesn't give abbreviations.
#
# From Paul Eggert (2016-12-19):
# Here are URLs for the 1918 and 1966 legislation:
# http://uscode.house.gov/statviewer.htm?volume=40&page=451
# http://uscode.house.gov/statviewer.htm?volume=80&page=108
# Although the 1918 names were officially "United States Standard
# Eastern Time" and similarly for "Central", "Mountain", "Pacific",
# and "Alaska", in practice "Standard" was placed just before "Time",
# as codified in 1966. In practice, Alaska time was abbreviated "AST"
# before 1968. Summarizing the 1967 name changes:
# 1918 names 1967 names
# -08 Standard Pacific Time (PST) Pacific standard time (PST)
# -09 (unofficial) Yukon (YST) Yukon standard time (YST)
# -10 Standard Alaska Time (AST) Alaska-Hawaii standard time (AHST)
# -11 (unofficial) Nome (NST) Bering standard time (BST)
#
# From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
# Public law 106-564 (2000-12-23) introduced ... "Chamorro Standard Time"
# for time in Guam and the Northern Marianas. See the file "australasia".
#
# From Paul Eggert (2015-04-17):
# HST and HDT are standardized abbreviations for Hawaii-Aleutian
# standard and daylight times. See section 9.47 (p 234) of the
# U.S. Government Printing Office Style Manual (2008)
# https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
# From Arthur David Olson, 2005-08-09
# The following was signed into law on 2005-08-08.
#
# H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS.
# (a) Amendment.--Section 3(a) of the Uniform Time Act of 1966 (15
# U.S.C. 260a(a)) is amended--
# (1) by striking "first Sunday of April" and inserting "second
# Sunday of March"; and
# (2) by striking "last Sunday of October" and inserting "first
# Sunday of November'.
# (b) Effective Date.--Subsection (a) shall take effect 1 year after the
# date of enactment of this Act or March 1, 2007, whichever is later.
# (c) Report to Congress.--Not later than 9 months after the effective
# date stated in subsection (b), the Secretary shall report to Congress
# on the impact of this section on energy consumption in the United
# States.
# (d) Right to Revert.--Congress retains the right to revert the
# Daylight Saving Time back to the 2005 time schedules once the
# Department study is complete.
# US eastern time, represented by New York
# Connecticut, Delaware, District of Columbia, most of Florida,
# Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky
# (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts,
# New Hampshire, New Jersey, New York, North Carolina, Ohio,
# Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
# Vermont, Virginia, West Virginia
# From Dave Cantor (2004-11-02):
# Early this summer I had the occasion to visit the Mount Washington
# Observatory weather station atop (of course!) Mount Washington [, NH]....
# One of the staff members said that the station was on Eastern Standard Time
# and didn't change their clocks for Daylight Saving ... so that their
# reports will always have times which are 5 hours behind UTC.
# From Paul Eggert (2005-08-26):
# According to today's Huntsville Times
# http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/1125047783228320.xml&coll=1
# a few towns on Alabama's "eastern border with Georgia, such as Phenix City
# in Russell County, Lanett in Chambers County and some towns in Lee County,
# set their watches and clocks on Eastern time." It quotes H.H. "Bubba"
# Roberts, city administrator in Phenix City. as saying "We are in the Central
# time zone, but we do go by the Eastern time zone because so many people work
# in Columbus."
#
# From Paul Eggert (2017-02-22):
# Four cities are involved. The two not mentioned above are Smiths Station
# and Valley. Barbara Brooks, Valley's assistant treasurer, heard it started
# because West Point Pepperell textile mills were in Alabama while the
# corporate office was in Georgia, and residents voted to keep Eastern
# time even after the mills closed. See: Kazek K. Did you know which
# Alabama towns are in a different time zone? al.com 2017-02-06.
# http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html
# From Paul Eggert (2014-09-06):
# Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
# says that New York City Hall time was 3 minutes 58.4 seconds fast of
# Eastern time (i.e., -4:56:01.6) just before the 1883 switch. Round to the
# nearest second.
# Rule NAME FROM TO - IN ON AT SAVE LETTER
Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
Rule NYC 1920 only - Oct lastSun 2:00 0 S
Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:03:58
-5:00 US E%sT 1920
-5:00 NYC E%sT 1942
-5:00 US E%sT 1946
-5:00 NYC E%sT 1967
-5:00 US E%sT
# US central time, represented by Chicago
# Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
# Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
# Washington counties), Illinois, western Indiana
# (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
# Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
# Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
# Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
# western Tennessee, most of Texas, Wisconsin
# From Paul Eggert (2018-01-07):
# In 1869 the Chicago Astronomical Society contracted with the city to keep
# time. Though delayed by the Great Fire, by 1880 a wire ran from the
# Dearborn Observatory (on the University of Chicago campus) to City Hall,
# which then sent signals to police and fire stations. However, railroads got
# their time signals from the Allegheny Observatory, the Madison Observatory,
# the Ann Arbor Observatory, etc., so their clocks did not agree with each
# other or with the city's official time. The confusion took some years to
# clear up. See:
# Moser M. How Chicago gave America its time zones. Chicago. 2018-01-04.
# http://www.chicagomag.com/city-life/January-2018/How-Chicago-Gave-America-Its-Time-Zones/
# From Larry M. Smith (2006-04-26) re Wisconsin:
# https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
# is currently enforced at the 01:00 time of change. Because the local
# "bar time" in the state corresponds to 02:00, a number of citations
# are issued for the "sale of class 'B' alcohol after prohibited
# hours" within the deviated hour of this change every year....
#
# From Douglas R. Bomberg (2007-03-12):
# Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
# Statue 175 closer in synch with the US Congress' intent....
# https://docs.legis.wisconsin.gov/2007/related/acts/3
# From an email administrator of the City of Fort Pierre, SD (2015-12-21):
# Fort Pierre is technically located in the Mountain time zone as is
# the rest of Stanley County. Most of Stanley County and Fort Pierre
# uses the Central time zone due to doing most of their business in
# Pierre so it simplifies schedules. I have lived in Stanley County
# all my life and it has been that way since I can remember. (43 years!)
#
# From Paul Eggert (2015-12-25):
# Assume this practice predates 1970, so Fort Pierre can use America/Chicago.
# From Paul Eggert (2015-04-06):
# In 1950s Nashville a public clock had dueling faces, one for conservatives
# and the other for liberals; the two sides didn't agree about the time of day.
# I haven't found a photo of this clock, nor have I tracked down the TIME
# magazine report cited below, but here's the story as told by the late
# American journalist John Seigenthaler, who was there:
#
# "The two [newspaper] owners held strongly contrasting political and
# ideological views. Evans was a New South liberal, Stahlman an Old South
# conservative, and their two papers frequently clashed editorially, often on
# the same day.... In the 1950s as the state legislature was grappling with
# the question of whether to approve daylight saving time for the entire state,
# TIME magazine reported:
#
# "'The Nashville Banner and The Nashville Tennessean rarely agree on anything
# but the time of day - and last week they couldn't agree on that.'
#
# "It was all too true. The clock on the front of the building had two faces -
# The Tennessean side of the building facing west, the other, east. When it
# was high noon Banner time, it was 11 a.m. Tennessean time."
#
# Seigenthaler J. For 100 years, Tennessean had it covered.
# The Tennessean 2007-05-11, republished 2015-04-06.
# https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/
# Rule NAME FROM TO - IN ON AT SAVE LETTER
Rule Chicago 1920 only - Jun 13 2:00 1:00 D
Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:09:24
-6:00 US C%sT 1920
-6:00 Chicago C%sT 1936 Mar 1 2:00
-5:00 - EST 1936 Nov 15 2:00
-6:00 Chicago C%sT 1942
-6:00 US C%sT 1946
-6:00 Chicago C%sT 1967
-6:00 US C%sT
# Oliver County, ND switched from mountain to central time on 1992-10-25.
Zone America/North_Dakota/Center -6:45:12 - LMT 1883 Nov 18 12:14:48
-7:00 US M%sT 1992 Oct 25 2:00
-6:00 US C%sT
# Morton County, ND, switched from mountain to central time on
# 2003-10-26, except for the area around Mandan which was already central time.
# See 