JST stands for Japan Standard Time. It is UTC+09:00 from UTC — 9 hours ahead of UTC — and it is used in Asia, in Tokyo, Osaka. JST is UTC+09:00 all year. Japan last observed daylight saving in 1951 and has not used it since.
Try the tool: UTC Converter — convert any time to and from JST, with the offset for the date you choose.
When is JST in effect?
JST is in effect all year. The places that use it do not observe daylight saving, so there is no summer abbreviation and no clock change to remember — the offset is UTC+09:00 in January and in July, and the abbreviation is the same in both. That is why JST is one of the easiest abbreviations to remember: it never changes. That stability is the reason these places are the easiest to schedule with: the gap between Tokyo and any other city changes only when the other city moves its clocks, never because of a change at this end. If you call the same city every week, the offset you learn is the offset all year.
What time is it when it is 12:00 JST?
| City | Local time when it is 12:00 JST (15 January 2026) |
|---|---|
| New York | 10:00 pm |
| London | 3:00 am |
| Paris | 4:00 am |
| Dubai | 7:00 am |
| Mumbai | 8:30 am |
| Tokyo | 12:00 pm |
| Sydney | 2:00 pm |
| Los Angeles | 7:00 pm |
The table is worked out from the offsets: 12:00 JST is 3:00 am UTC, and each city's local time is UTC plus its own offset. The half-hour cities are the ones to watch: Mumbai is 30 minutes past the hour, because India is on UTC+05:30. The UTC converter does this calculation for any city and any date.
Does JST have a daylight saving counterpart?
No. JST is used all year, because the places that use it do not observe daylight saving — so there is no summer abbreviation to switch to and no clock change to remember. That is simpler, but it has a consequence: the gap between JST and a place that does observe daylight saving changes during the year. In winter, Tokyo and New York are 14 hours apart; in summer, when New York moves to EDT (UTC−04:00), the gap becomes 13 hours. The time zone converter applies the rules for the date you choose, so the gap is always right.
JST through the year
Whether JST is in effect in each month of 2026, for Tokyo:
| Month | JST in effect? | Offset in effect |
|---|---|---|
| January | Yes | UTC+09:00 |
| February | Yes | UTC+09:00 |
| March | Yes | UTC+09:00 |
| April | Yes | UTC+09:00 |
| May | Yes | UTC+09:00 |
| June | Yes | UTC+09:00 |
| July | Yes | UTC+09:00 |
| August | Yes | UTC+09:00 |
| September | Yes | UTC+09:00 |
| October | Yes | UTC+09:00 |
| November | Yes | UTC+09:00 |
| December | Yes | UTC+09:00 |
JST is in effect in every month, because the places that use it do not observe daylight saving — the offset is UTC+09:00 in January and in July, and there is no month in which another abbreviation takes over. The UTC converter shows the offset in effect on any date.
What time is it when it is 09:00 JST?
Nine in the morning is the start of the working day, so it is the time that matters for meetings. When it is 09:00 JST on 15 January 2026, the time in eight major cities is:
| City | Local time at 09:00 JST |
|---|---|
| New York | 7:00 pm |
| London | 12:00 am |
| Paris | 1:00 am |
| Dubai | 4:00 am |
| Mumbai | 5:30 am |
| Tokyo | 9:00 am |
| Sydney | 11:00 am |
| Los Angeles | 4:00 pm |
JST and UTC, worked both ways
Converting from JST to UTC: subtract the offset. 09:00 JST is 12:00 am UTC, and 15:00 JST is 6:00 am UTC. Converting from UTC to JST: add the offset. 12:00 UTC is 9:00 pm JST, and 18:00 UTC is 3:00 am JST. If the result crosses midnight, the date changes: 8:00 am is the time in JST when it is 23:00 UTC, and if that is past midnight it is the next day. The UTC converter does both directions for any time and any date.
Common mistakes with JST
The commonest mistake is using JST for the wrong season: writing EST in July, when New York is on EDT, or writing EDT in January, when it is on EST. The second mistake is forgetting the place: EST means different things in North America (UTC−05:00) and Australia (UTC+10:00), and CST means different things in North America (UTC−06:00), China (UTC+08:00) and Cuba (UTC−05:00). The fix for both is the same: write the offset with the abbreviation, and check the date. The time zone converter shows the offset for any city on any date, so there is no need to guess.
Frequently asked questions
What does JST stand for?
Japan Standard Time. It is UTC+09:00 from UTC, and it is used in Asia, in Tokyo, Osaka.
What is the UTC offset of JST?
UTC+09:00. That means JST is 9 hours ahead of UTC: when it is 12:00 UTC it is 9:00 pm JST.
When is JST used?
All year. The places that use JST do not observe daylight saving, so the abbreviation never changes.
What cities use JST?
Tokyo, Osaka. JST is UTC+09:00 all year. Japan last observed daylight saving in 1951 and has not used it since.
How do I convert JST to my time?
Convert JST to UTC first — subtract UTC+09:00 — then add your own offset. Or use the UTC converter: enter the time in JST and it gives the time in any city.
Is JST the same as UTC?
No. JST is UTC+09:00 from UTC, and it is used all year — it has no daylight saving counterpart.
What time is it in JST now?
The UTC converter shows the current time in JST live — it is UTC plus UTC+09:00. Because JST is in effect all year, the time is always UTC plus UTC+09:00.
Related pages
Sources
- IANA Time Zone Database, via Node.js Intl (
Intl.DateTimeFormatwithtimeZone) — offsets, daylight saving dates and local times in this article were worked out from the IANA database, not typed from memory. - TimeFlow's own time-zone data (
data/cities.ts,data/dst.ts), computed from the IANA database. - Time zone rules and offsets: the IANA Time Zone Database, as applied by this site's tools. Offsets on this page are computed from the database for the dates stated.
- TimeFlow's UTC converter and time zone converter — the live tools behind the numbers on this page.
- Time-zone and daylight saving rules are set by governments and can change. For flights, deadlines and meetings that cannot move, confirm the time with an official source.