Hawaii–Aleutian Time Zone

The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST),[1][2] by subtracting ten hours from Coordinated Universal Time (UTC−10:00). The clock time in this zone is based on the mean solar time of the 150th meridian west of the Greenwich Observatory.

Hawaii–Aleutian Time Zone
UTC offset
Current time
11:26, 12 August 2020 HAST [refresh]
12:26, 12 August 2020 HADT [refresh]
Observance of DST
DST is observed in some of this time zone.

The zone takes its name from the two areas it includes: Hawaii and the portion of Alaska's Aleutian Islands west of 169° 30′ W longitude.

During daylight saving time (DST), the Alaskan portion observes Hawaii–Aleutian Daylight Time (HDT, UTC−09:00), while Hawaii stays on standard time.

From 1900 until 1947, UTC−10:30 was used as standard time in Hawaii.[3]

French Polynesia uses UTC−10:00 for its major cities. The Cook Islands 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.

Major metropolitan areasEdit

Other significant placesEdit

See alsoEdit


  1. ^ "U.S. Government Printing Office Style Manual: An official guide to the form and style of Federal Government printing" (PDF). U.S. Government Printing Office. 2008. p. 234. Retrieved 2017-07-24. Time zones §9.47. The following forms are to be used when abbreviating names of time zones: ... HDT—Hawaii-Aleutian daylight time (not observed in HI) ... HST—Hawaii-Aleutian standard time
  2. ^ "What are the time zones in the United States?". National Institute of Standards and Technology, U.S. Department of Commerce. 2016. Retrieved 2017-07-24. Hawaii-Aleutian (HT); HST -10; HDT -9; DST observed in Aleutian Islands, but not Hawaii
  3. ^ "Sources for Time Zone and Daylight Saving Time Data". Archived from the original on 2012-06-23. Retrieved 2012-06-18.[failed verification]

External linksEdit