Hawaii–Aleutian Time Zone Hawaii–Aleutian Time Zone The Hawaii–Aleutian Time Zone observes Hawaii–Aleutian Standard Time (HST), by subtracting ten hours from Coordinated Universal Time (). 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 daylight saving time, the Alaskan portion observes Hawaii–Aleutian Daylight Time (HDT, ), while Hawaii stays on standard time. From 1900 until 1947, GMT−10:30 was used as standard time in Hawaii. French
Aleutian Islands Aleutian Islands The Aleutian Islands (; ; , literally "Land of the Aleuts", possibly from Chukchi "aliat", "island") are a chain of 14 large volcanic islands and 55 smaller ones belonging to both the U.S. state of Alaska and the Russian federal subject of Kamchatka Krai. They form part of the Aleutian Arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km) and extending about westward from the Alaska Peninsula toward the Kamchatka Peninsula in Russia, and mark a dividing line between the Bering Sea to the north and the Pacific Ocean to the south.