Alaska Time Zone - History

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. Some references prior to 1967 refer to this zone as Central Alaska Standard Time (CAT) or as Alaska Standard Time (AST). In 1966, the Uniform Time Act renamed the UTC−10 zone to Alaska-Hawaii Standard Time (AHST), effective April 1, 1967. 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.