JST to London
United Kingdom Time is 8 hours behind Japan Standard Time for 210 days of the year, and takes 2 different values across the year.
JST to London conversion table
Every hour of the day at the difference that holds for 210 days of 2026 — 8 hours. See “When the difference changes” below for the rest.
| JST | London |
|---|---|
| 12:00 AM | 4:00 PM −1 day |
| 1:00 AM | 5:00 PM −1 day |
| 2:00 AM | 6:00 PM −1 day |
| 3:00 AM | 7:00 PM −1 day |
| 4:00 AM | 8:00 PM −1 day |
| 5:00 AM | 9:00 PM −1 day |
| 6:00 AM | 10:00 PM −1 day |
| 7:00 AM | 11:00 PM −1 day |
| 8:00 AM | 12:00 AM |
| 9:00 AM | 1:00 AM |
| 10:00 AM | 2:00 AM |
| 11:00 AM | 3:00 AM |
| JST | London |
|---|---|
| 12:00 PM | 4:00 AM |
| 1:00 PM | 5:00 AM |
| 2:00 PM | 6:00 AM |
| 3:00 PM | 7:00 AM |
| 4:00 PM | 8:00 AM |
| 5:00 PM | 9:00 AM |
| 6:00 PM | 10:00 AM |
| 7:00 PM | 11:00 AM |
| 8:00 PM | 12:00 PM |
| 9:00 PM | 1:00 PM |
| 10:00 PM | 2:00 PM |
| 11:00 PM | 3:00 PM |
Shared working hours
They do not overlap at all. A 09:00–17:00 working day in Japan Standard Time ends no time at all before the United Kingdom 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 London, or the other way round.
When the difference changes
The two zones move their clocks on different dates, so the gap takes more than one value. These are the stretches of 2026:
| Dates | London is | Why |
|---|---|---|
| 1 January – 29 March | 9 hours behind | — |
| 29 March – 25 October | 8 hours behind | United Kingdom Time clocks go forward one hour |
| 25 October – 1 January | 9 hours behind | United Kingdom Time clocks go back one hour |
Dates are Japan Standard Time local dates for 2026. Transition dates move by a few days from year to year; the rule each country follows does not.
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 United Kingdom Time
The United Kingdom is on GMT (UTC+0) for about five months and BST (UTC+1) for the rest, changing on the last Sunday in March and the last Sunday in October. Ireland keeps exactly the same clock, so every figure here applies to Dublin as well as London.
Cities on this clock: London, Lisbon, Dublin, Edinburgh, Manchester.
How the difference is worked out
The gap between Japan Standard Time and United Kingdom Time is not one number. The two zones change their clocks on different dates, so for part of the year the difference is 8 hours and for the rest it is something else — the table above lists each stretch of 2026 with the date it starts and which country's clocks moved.
With both zones on their own standard time — daylight saving not in force anywhere — United Kingdom 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 Europe/London. Nothing is looked up on a server and nothing about your visit is recorded.
Is London ahead of or behind JST?
United Kingdom Time is 8 hours behind Japan Standard Time for 210 days of the year, and takes 2 different values across the year. The gap moves because the two zones change their clocks on different dates — on 29 March, United Kingdom Time clocks go forward one hour; on 25 October, United Kingdom Time clocks go back one hour (dates for 2026).
What time is 9 AM JST in London?
9:00 AM JST is 1:00 AM London for most of the year — see the table above for the 3 stretches of 2026 the gap holds different values.
When can Japan Standard Time and United Kingdom Time meet?
They do not overlap. A 09:00–17:00 working day in Japan Standard Time ends no time at all before the United Kingdom Time one begins, so a call has to sit outside someone's working hours — early morning in Japan Standard Time or late evening in United Kingdom 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.