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
Southcentral Alaska Mount Wrangell. The Cook Inlet volcanoes, located in the Tordrillo Mountains and in the north end of the Aleutian Range, are newer, lie in the West, and include Mount Redoubt, Mount Iliamna, Hayes Volcano, Mount Augustine, Fourpeaked Mountain and Mount Spurr. Most recently, Augustine and Fourpeaked erupted in 2006, and Mount Redoubt erupted in March 2009, resulting in airplane flight cancellations. Southcentral Alaska Southcentral Alaska is the portion of the U.S. state of Alaska consisting of the shorelines and uplands of the central Gulf of Alaska. Most of the population of the state lives in this region, concentrated in and