JST to UTC
Coordinated Universal Time is 9 hours behind Japan Standard Time, all year round.
JST to UTC conversion table
Every hour of the day, Japan Standard Time to Coordinated Universal Time. The gap never changes, so this table holds on every date.
| JST | UTC |
|---|---|
| 12:00 AM | 3:00 PM −1 day |
| 1:00 AM | 4:00 PM −1 day |
| 2:00 AM | 5:00 PM −1 day |
| 3:00 AM | 6:00 PM −1 day |
| 4:00 AM | 7:00 PM −1 day |
| 5:00 AM | 8:00 PM −1 day |
| 6:00 AM | 9:00 PM −1 day |
| 7:00 AM | 10:00 PM −1 day |
| 8:00 AM | 11:00 PM −1 day |
| 9:00 AM | 12:00 AM |
| 10:00 AM | 1:00 AM |
| 11:00 AM | 2:00 AM |
| JST | UTC |
|---|---|
| 12:00 PM | 3:00 AM |
| 1:00 PM | 4:00 AM |
| 2:00 PM | 5:00 AM |
| 3:00 PM | 6:00 AM |
| 4:00 PM | 7:00 AM |
| 5:00 PM | 8:00 AM |
| 6:00 PM | 9:00 AM |
| 7:00 PM | 10:00 AM |
| 8:00 PM | 11:00 AM |
| 9:00 PM | 12:00 PM |
| 10:00 PM | 1:00 PM |
| 11:00 PM | 2:00 PM |
Shared working hours
They do not overlap at all. A 09:00–17:00 working day in Japan Standard Time ends 1 hour before the Coordinated Universal Time one begins, so any live call sits outside somebody's working hours.
The shortest reach is the edges: early morning in JST against late evening in UTC, or the other way round.
When the difference changes
It doesn't. Coordinated Universal Time is 9 hours behind Japan Standard Time on every date of the year. Japan Standard Time runs at UTC+09:00; Coordinated Universal Time runs at UTC+00:00.
About Japan Standard Time
Japan is a fixed UTC+9 and has had no daylight saving since 1951. It shares its clock with Korea exactly, so a schedule that works for Tokyo works unchanged for Seoul.
Cities on this clock: Tokyo, Osaka, Seoul.
About Coordinated Universal Time
UTC never shifts. It is the reference every other zone is defined against, which is why logs, flight schedules and protocol timestamps use it. GMT is the same clock for every civil purpose, so a query for one is answered by the other.
Cities on this clock: Reykjavik, Accra, Abidjan, Dakar.
Watch out: GMT is also used loosely to mean "UK time", and those are not the same thing for seven months of the year — the United Kingdom moves to BST (UTC+1) while UTC stays put.
How the difference is worked out
Neither Japan Standard Time nor Coordinated Universal Time moves its clock relative to the other, so coordinated universal time is 9 hours behind japan standard time is a rule rather than a fact about one particular year. The hour-by-hour table above holds on every date.
With both zones on their own standard time — daylight saving not in force anywhere — Coordinated Universal Time is 9 hours behind Japan Standard Time. That figure never changes; everything else on this page follows from it plus whichever clocks have moved.
Every figure here comes from the IANA time zone database via your browser's own Intl engine, using the zone ids Asia/Tokyo and UTC. Nothing is looked up on a server and nothing about your visit is recorded.
Is UTC ahead of or behind JST?
Coordinated Universal Time is 9 hours behind Japan Standard Time, all year round. Japan Standard Time runs at UTC+09:00; Coordinated Universal Time runs at UTC+00:00. Because neither zone changes its clock, the gap never moves.
What time is 9 AM JST in UTC?
9:00 AM JST is 12:00 AM UTC.
When can Japan Standard Time and Coordinated Universal Time meet?
They do not overlap. A 09:00–17:00 working day in Japan Standard Time ends 1 hour before the Coordinated Universal Time one begins, so a call has to sit outside someone's working hours — early morning in Japan Standard Time or late evening in Coordinated Universal Time is usually the shortest reach.
What does JST stand for?
JST is Japan Standard Time, also written Tokyo time, Japan time, Osaka time. Japan is a fixed UTC+9 and has had no daylight saving since 1951. It shares its clock with Korea exactly, so a schedule that works for Tokyo works unchanged for Seoul.