The Hawaii-Aleutian Time Zone observes Hawaii-Aleutian Standard Time (HAST), by subtracting ten hours from Coordinated Universal Time (UTC−10). The clock time in this zone is based on the mean solar time of the 150th meridian west of the Greenwich Observatory.
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 DST the Alaskan portion observes HADT while Hawaii does not.
From 1900 until 1947, GMT−10:30 was used as standard time in Hawaii. [1]
French Polynesia uses UTC−10 for its major cities. The Cook Islands also use the same time. These areas do not use DST.
| Hours from GMT | Standard time | Daylight saving | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| –10 | Hawaii-Aleutian | ||||||||||
| –9 | Alaska | Hawaii-Aleutian | |||||||||
| –8 | Pacific | Alaska | |||||||||
| –7 | Mountain | Pacific | |||||||||
| –6 | Central | Mountain | |||||||||
| –5 | Eastern | Central | |||||||||
| –4 | Atlantic | Eastern | |||||||||
| –3:30 | Newfoundland | ||||||||||
| –3 | Saint Pierre and Miquelon | Atlantic | |||||||||
| –2:30 | Newfoundland | ||||||||||
| –2 | Saint Pierre and Miquelon | ||||||||||
| See also: Time in Canada • Time in Mexico • Time in the United States | |||||||||||