The Hawaii-Aleutian Time Zone observes Hawaii-Aleutian Standard Time (HST), by subtracting ten hours from Coordinated Universal Time (UTC-10). The UTC−10 Time offset is used in Cook Islands French Polynesia Society Archipelago including The UTC−10 Time offset is used in Cook Islands French Polynesia Society Archipelago including The clock time in this zone is based on the mean solar time of the 150th degree meridian west of the Greenwich Observatory. Solar times are measures of the apparent position of the Sun on the Celestial sphere. This article is about the geographical concept For other uses of the word see Meridian. The Royal Observatory Greenwich (formerly the Royal Greenwich Observatory or RGO) was commissioned in 1675 by King Charles II, with the
The zone also includes Alaska's Aleutian Islands west of 169° 30′ west, along with Hawaii. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic The State of Hawaii ( or həˈwaɪʔiː Hawaiian: Mokuāina o Hawaii) is a state in the United States located on an Archipelago in the The portion in the Aleutian islands observes DST while Hawaii does not. Daylight saving time ( DST
Hawaii used a standard time of GMT-10:30 from 1900 until 1947, when clocks were changed to the present -10:00 zone. Standard time is the result of synchronizing clocks in different geographical locations within a Time zone to the same time rather than using the local meridian as Greenwich Mean Time ( GMT) is a term originally referring to mean solar time at the Royal Observatory in Greenwich, London 
Honolulu is the Capital and most populous Census-designated place (CDP in the U A time offset is defined by international convention as a number of hours and minutes from Coordinated Universal Time in Greenwich England.