The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST) by subtracting ten hours from

Coordinated Universal Time Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communicat ...

( UTC−10:00). The clock time in this zone is based on the

mean solar time Solar time is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the day, based on the synodic rotation period. Traditionally, there are three types of time reckoning based ...

of the 150th meridian west of the Greenwich Observatory. The zone takes its name from the two areas it includes:

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

and the portion of

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

west of 169° 30 W longitude. During

daylight saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...

(DST), the Alaskan portion observes Hawaii–Aleutian Daylight Time (HDT, UTC−09:00), while Hawaii stays on standard time. Hawaii has not observed daylight saving time since September 1945. Until 1947, UTC−10:30 was used as

standard time Standard time is the synchronization of clocks within a geographical region to a single time standard, rather than a local mean time standard. Generally, standard time agrees with the local mean time at some meridian that passes through the r ...

in Hawaii. On June 8 of that year, a new territorial law moved Hawaiian Standard Time 30 minutes ahead. Hawaii–Aleutian Standard Time was established to maintain consistency in the scheduling of business and government activities across Hawaii and the Aleutian Islands.

French Polynesia French Polynesia ( ; ; ) is an overseas collectivity of France and its sole #Governance, overseas country. It comprises 121 geographically dispersed islands and atolls stretching over more than in the Pacific Ocean, South Pacific Ocean. The t ...

uses UTC−10:00 for its major cities. The

Cook Islands The Cook Islands is an island country in Polynesia, part of Oceania in the South Pacific Ocean. It consists of 15 islands whose total land area is approximately . The Cook Islands' Exclusive Economic Zone (EEZ) covers of ocean. Avarua is its ...

also use the same time. These areas do not use DST. "Hawaii–Aleutian Time Zone" is a U.S. term and for that reason the Polynesian areas are not considered to be a part of the Hawaii–Aleutian Time Zone. The largest city and metropolitan area in the Hawaii–Aleutian Time Zone are

Honolulu Honolulu ( ; ) is the List of capitals in the United States, capital and most populous city of the U.S. state of Hawaii, located in the Pacific Ocean. It is the county seat of the Consolidated city-county, consolidated City and County of Honol ...

and its metropolitan area, respectively.

Major metropolitan areas

Honolulu, Hawaii Honolulu ( ; ) is the List of capitals in the United States, capital and most populous city of the U.S. state of Hawaii, located in the Pacific Ocean. It is the county seat of the Consolidated city-county, consolidated City and County of Honol ...

* Hilo, Hawaii * Kahului, Hawaii * Kailua-Kona, Hawaii * Kapaa, Hawaii

Other significant places

* Adak Island, Alaska *

Johnston Atoll Johnston Atoll is an Unincorporated territories of the United States, unincorporated territory of the United States, under the jurisdiction of the United States Air Force (USAF). The island is closed to public entry, and limited access for mana ...

References

External links

HST – Hawaii–Aleutian Standard TimeThe official U.S. time for the Hawaii–Aleutian time zone (Hawaii)
''dead link''
The official U.S. time for the Hawaii–Aleutian time zone (Aleutian Islands)
''dead link''
What are the time zones in the United States? (NIST)

Hawaiian-Aleutian zone at Cornell
Time zones Time zones in the United States {{Hawaii-stub

Major metropolitan areas

Other significant places

See also

References

External links