Time in Alaska

Alaska is covered by two time zones, as described below:

• Islands west of -169.5° (169°30'W) are in the Hawaii–Aleutian Time Zone (UTC−10:00, DST UTC−09:00). Daylight saving time (DST) is observed.
• The town of Hyder, because it essentially is a single town split by the US-Canada border with roads only to Canada, unofficially observes Pacific Time including DST (UTC−08:00, DST UTC−07:00) like its neighbor Stewart, British Columbia, with the exception of the U.S. Post Office (because it is a federal facility).[1]
• The rest of the state is in the Alaska Time Zone and observes DST (UTC−09:00, DST UTC−08:00).

History

In 1901, Alaska started to use time zones.[2] Before time zones were introduced, every place used local observation of the sun to set their clocks, which means they used local mean time, every city different based on their longitude. On 18 October 1867 Alaska changed from belonging to Russia (Russian America), to belonging to the United States (the Alaska Purchase). Before this event, Alaska used the same date as Asia. The capital was Sitka (135.3345°W) which had local time +14:59 before 1867 and -9:01 afterwards. This means that Alaska repeated one day in the calendar, but also because of the switch from the Julian calendar to the Gregorian calendar, Alaska also skipped 12 days, so that Friday, October 6 was followed by Friday, October 18. (Fri 6 Oct, Julian, followed by Fri 6 Oct Julian as the day repeats due to the date line shift, which is Fri 18 Oct Gregorian.).

Because of the calendar which diverged by 11 or 12 days from the modern calendar used in most of Europe (except Greece, Ukraine, the Russian Empire, the Ottoman Empire, Bulgaria, Estonia, Yugoslavia, the Courland Governorate (reverted to the Julian calendar between 1796 and 1915), the Lithuania Governorate (reverted to the Julian calendar between 1800 and 1915), and Romania did not adopt the reformed calendar until no later than 1923), it is possible to say that before 1867 used:

Period in use	Time offset from GMT	Name of time
before February 28 (O.S. February 17), 1800	UTC−249:01 (in Sitka)	local mean time
	UTC−252:30:14 (in westernmost island)
	UTC−248:39:59 (in easternmost area)
March 1 (O.S. February 18), 1800 – October 18 (O.S. October 6), 1867	UTC−273:01 (in Sitka)	local mean time
	UTC−276:30:14 (in westernmost island)
	UTC−272:39:59 (in easternmost area)
October 18, 1867 – August 20, 1900	UTC−09:01 (in Sitka)	local mean time
	UTC−12:30:14 (in westernmost island)
	UTC−08:39:59 (in easternmost area)

From 1901 until 1983 there were the following time zones:

• Nome, Adak and the west coast and the Aleutians used UTC–11:00.[3][4]
• Anchorage, Fairbanks and most of surrounding areas used UTC-10:00.[2]
• Yakutat used UTC–09:00.[5]
• Juneau and all of the southeast used UTC–08:00.[6]

In 1942–1945 all of the US including Alaska added one hour compared to other years. In 1967 Daylight saving time was introduced in the US including Alaska.

In 1983 Alaska skipped two zones and kept only two time zones, Alaska and Aleutian time, where Aleutian has UTC-10:00 and all other parts of Alaska has UTC-09:00.[7] One hour Daylight saving time is added in summer.

tz database

The tz database version 2017c contains seven time zones for Alaska for historical reasons. Only three (America/Adak, America/Anchorage, and America/Metlakatla) are currently in use.

CC	Coordinates	TZ	Comments	UTC offset	UTC offset DST	Notes
US	[phone]	America/Anchorage	Alaska Time	−09:00	−08:00
US	[phone]	America/Juneau	Alaska Time - Alaska panhandle	−09:00	−08:00
US	[phone]	America/Sitka	Alaska Time - southeast Alaska panhandle	−09:00	−08:00
US	[phone]	America/Yakutat	Alaska Time - Alaska panhandle neck	−09:00	−08:00
US	[phone]	America/Nome	Alaska Time - west Alaska	−09:00	−08:00
US	[phone]	America/Adak	Aleutian Islands	−10:00	−09:00
US	[phone]	America/Metlakatla	Metlakatla Time - Annette Island	−08:00	−08:00

References

1. "Exceptions, Oddities and Notes". OnTimeZone.com. Retrieved 2012-06-17.
2. Time Zones - Anchorage
3. Time Zones - Nome
4. Time Zones - Adak
5. Time Zones - Yakutat
6. Time Zones - Juneau
7. Wallace Turner (1983-11-01). "Alaska's four time zones now two". The New York Times. Retrieved 2017-09-21. The big change was in Juneau, Ketchikan and Sitka, the major towns in southeast Alaska, where clocks shifted back two hours to Yukon time. After decades on Pacific time, this region will now be an hour earlier, as will Anchorage and Fairbanks, which formerly were two hours earlier than Pacific time.