The Hawaii-Aleutian Time Zone observes Hawaii-Aleutian Daylight Time (HADT), by subtracting nine hours from Coordinated Universal Time (UTC−9). 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 portion of Alaska's Aleutian Islands west of 169° 30′ W longitude. During DST the Alaskan portion observes HADT while Hawaii continues to observe HAST time.
| 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 | |||||||||||