Japan time zone history
Japan has kept UTC+9 since 1888, with no clock changes since 1970, the seventh-longest run of the 148 zones with no change of standard time since 1970. Tokyo left local mean time (UTC+9:18:59) in 1888, the earliest switch of the 9 zones on UTC+9 standard time.
UTC+9
Standard time is UTC+9 (JST) all year under the current rules.
UTC+9 every day since 1970
Before 1970
Standard time changes
| Date | Change | New standard time | Clock label |
|---|---|---|---|
| Before 1970 | |||
| January 1, 1888 | Local mean time (UTC+9:18:59) replaced | UTC+9 | JST |
Daylight saving periods
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| 1948 | May 2 | September 12 | 1 hour, JST to JDT |
| 1949 | April 3 | September 11 | 1 hour, JST to JDT |
| 1950–1951 | first Sunday in May, 00:00 | second Sunday in September, 01:00 | 1 hour, JST to JDT |
Also on UTC+9
South Korea, North Korea, Chita (Russia), Yakutsk (Russia), Khandyga (Russia), Palau, Jayapura (Indonesia) and East Timor.
Clocks next door since 1970
- Vladivostok (Russia) (1,070 km): usually 1 hour ahead; different on 7,185 days in 1981–2014.
- South Korea (1,159 km): same time except 308 days in 1987 and 1988.
- Sakhalin (Russia) (1,282 km): usually 2 hours ahead; different on 5,512 days in 1981–2011 and 2014–2016.
- North Korea (1,291 km): same time except 994 days in 2015–2018.
- Shanghai (China) (1,763 km): usually 1 hour behind; different on 896 days in 1986–1991.
How it compares
On standard time, clocks in Tokyo run 19 minutes behind local mean solar time.