GMT to JST converter
JST is 9 hours ahead of GMT right now. Live clocks on both sides, a direct time input, the full 24-hour table with a permalink per hour, and the real daylight-saving state — computed from the IANA tz database on every request, never from a stored offset.
Convert an exact time type it — no sliders
Conversion runs in your browser against the same IANA rules the server uses, so it keeps working offline and nothing you type is sent anywhere.
Daylight saving right now
Japan Standard Time
Asia/Tokyo is currently on JST (UTC+09:00).
no clock change scheduled — this zone is fixed at UTC+09:00
Japan Standard Time is UTC+9 with no daylight saving — Japan has not observed DST since 1951, so the offset is safe to hard-code.
Greenwich Mean Time
Etc/GMT is on GMT (UTC+00:00).
no clock change scheduled — fixed at UTC+00:00
GMT is UTC+0 and never shifts. The UK observes GMT in winter only — in summer it is on BST (UTC+1), so "GMT" on a British invite dated in July usually means BST.
Best time to call green = 09:00–18:00 on both sides
No overlap inside a 09:00–18:00 day on both sides. Someone has to take an early or late slot — the table below shows exactly which hours are least bad.
GMT to JST, hour by hour 13 August 2026 · every row is a permalink
| GMT | JST | 12-hour | Day | Permalink |
|---|---|---|---|---|
| 00:00 | 09:00 JST | 9:00 AM | same day | 00:00 → |
| 01:00 | 10:00 JST | 10:00 AM | same day | 01:00 → |
| 02:00 | 11:00 JST | 11:00 AM | same day | 02:00 → |
| 03:00 | 12:00 JST | 12:00 PM | same day | 03:00 → |
| 04:00 | 13:00 JST | 1:00 PM | same day | 04:00 → |
| 05:00 | 14:00 JST | 2:00 PM | same day | 05:00 → |
| 06:00 | 15:00 JST | 3:00 PM | same day | 06:00 → |
| 07:00 | 16:00 JST | 4:00 PM | same day | 07:00 → |
| 08:00 | 17:00 JST | 5:00 PM | same day | 08:00 → |
| 09:00 | 18:00 JST | 6:00 PM | same day | 09:00 → |
| 10:00 | 19:00 JST | 7:00 PM | same day | 10:00 → |
| 11:00 | 20:00 JST | 8:00 PM | same day | 11:00 → |
| 12:00 | 21:00 JST | 9:00 PM | same day | 12:00 → |
| 13:00 | 22:00 JST | 10:00 PM | same day | 13:00 → |
| 14:00 | 23:00 JST | 11:00 PM | same day | 14:00 → |
| 15:00 | 00:00 JST | 12:00 AM | next day | 15:00 → |
| 16:00 | 01:00 JST | 1:00 AM | next day | 16:00 → |
| 17:00 | 02:00 JST | 2:00 AM | next day | 17:00 → |
| 18:00 | 03:00 JST | 3:00 AM | next day | 18:00 → |
| 19:00 | 04:00 JST | 4:00 AM | next day | 19:00 → |
| 20:00 | 05:00 JST | 5:00 AM | next day | 20:00 → |
| 21:00 | 06:00 JST | 6:00 AM | next day | 21:00 → |
| 22:00 | 07:00 JST | 7:00 AM | next day | 22:00 → |
| 23:00 | 08:00 JST | 8:00 AM | next day | 23:00 → |