JST — Japan Standard Time

Japan Standard Time (JST) is nine hours ahead of Coordinated Universal Time and is used throughout Japan. The time is based on the 135th meridian east, which passes through Akashi in Hyogo Prefecture, where the Akashi Municipal Planetarium marks the exact location. JST has been in continuous use since January 1, 1888, when Japan adopted a standardized time system to replace the traditional Japanese timekeeping method that divided day and night into six varying-length periods.

Tokyo, the world's largest metropolitan area by population, is the most prominent city in this time zone. JST is shared with South Korea (where it is called Korea Standard Time, KST) and with the Indonesian province of Eastern Indonesia (WIT). Japan's position nine hours ahead of London and fourteen hours ahead of New York means that the Tokyo Stock Exchange opens before European markets and closes before American markets begin their trading day.

Japan does not observe daylight saving time. The country used DST during the Allied occupation from 1948 to 1951, but it was unpopular and abolished after the occupation ended. Despite periodic proposals to reintroduce DST, particularly around energy conservation efforts and the 2020 Tokyo Olympics, the Japanese government has consistently declined to adopt the practice.