|
The Alaska Time Zone observes standard time by subtracting nine hours from Coordinated Universal Time (UTC−09:00). During daylight saving time its time offset is eight hours (UTC−08:00). The clock time in this zone is based on mean solar time at the 135th meridian west of the Greenwich Observatory. The zone includes nearly all of the U.S. state of Alaska and is one hour behind the Pacific Time Zone. *standard time: Alaska Standard Time (AKST) *daylight saving time: Alaska Daylight Time (AKDT) The western Aleutian Islands observe Hawaii–Aleutian Time, one hour behind the remainder of the state. Effective from 2007, the local time changes from AKST to AKDT at 02:00 LST to 03:00 LDT on the second Sunday in March and returns at 02:00 LDT to 01:00 LST on the first Sunday in November. ==History== The Standard Time Act of 1918 authorized the Interstate Commerce Commission to define each time zone. The United States Standard Alaska Time was designated as UTC−10.〔(【引用サイトリンク】title=Full text - Daylight Saving Time - U.S. Law, 1918 & 1942 )〕 Some references prior to 1967 refer to this zone as Central Alaska Standard Time (CAT)〔(【引用サイトリンク】title=Time zone names- Central Africa Time, Central Alaskan Standard Time(until 1967) )〕 or as Alaska Standard Time (AST). In 1966, the Uniform Time Act renamed the UTC−10 zone to Alaska-Hawaii Standard Time〔(【引用サイトリンク】title=US CODE: Title 15,263. Designation of zone standard times )〕 (AHST〔(【引用サイトリンク】title=Time zone names- Alaska-Hawaii Standard Time )〕), effective April 1, 1967.〔(【引用サイトリンク】title=United States Time Notes )〕 This zone was renamed in 1983〔 to Hawaii-Aleutian Standard Time (HAST) when most of Alaska was moved out of the zone. The Alaska Time Zone (UTC−9) is what was previously known as the Yukon Standard Time Zone (YST). However, the Yukon Territory switched to the Pacific Standard Time Zone in 1975 and the time zone was not used (except for Yakutat) until 1983 when the state of Alaska decided to move most of the state to UTC−9. Prior to that the Alaska Panhandle communities were in the Pacific Time Zone, while most of the interior was on UTC−10. Nome and the Aleutians previously observed Bering Standard Time or UTC−11. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alaska Time Zone」の詳細全文を読む スポンサード リンク
|