Observatory log
Tokyo and Uummannaq, compared
- 01Difference now
Uummannaq is 10 hours behind Tokyo.
Tokyo: JST (UTC+9) · Uummannaq: UTC−1 (UTC−1)
Next changeFrom 24 October 2026: Uummannaq is 11 hours behind Tokyo.
- 02Through 2026–2027
- 1 January 2026 – 29 March 2026−11 h
- 29 March 2026 – 24 October 2026−10 h
- 24 October 2026 – 28 March 2027−11 h
- 28 March 2027 – 30 October 2027−10 h
- 30 October 2027 – 31 December 2027−11 h
Difference of Uummannaq from Tokyo. It changes on the days either place changes its clocks (dates local to that place).
- 03Shared working hours
Their working days never overlap.
Counted as 09:00–17:00 local time on each place’s own working days, for the next seven days.
- 04Best time to meet
19:00–22:00 in Tokyo = 09:00–12:00 in Uummannaq
No shared office hours: this is early or late for one side (Mon–Fri).
Also possible: Mon–Fri: 16:00–17:00 in Tokyo = 06:00–07:00 in Uummannaq · 1 h.
- 05Weekend
Tokyo: Saturday and Sunday
Uummannaq: Saturday and Sunday
24 hours
A day in Tokyo, in Uummannaq
| Tokyo | Uummannaq | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 14:00Yesterday | |
| 01:00 | 15:00Yesterday | |
| 02:00 | 16:00Yesterday | |
| 03:00 | 17:00Yesterday | |
| 04:00 | 18:00Yesterday | |
| 05:00 | 19:00Yesterday | |
| 06:00 | 20:00Yesterday | |
| 07:00 | 21:00Yesterday | |
| 08:00 | 22:00Yesterday | |
| 09:00 | 23:00Yesterday | |
| 10:00 | 00:00 | |
| 11:00 | 01:00 | |
| 12:00 | 02:00 | |
| 13:00 | 03:00 | |
| 14:00 | 04:00 | |
| 15:00 | 05:00 | |
| 16:00 | 06:00 | |
| 17:00 | 07:00 | |
| 18:00 | 08:00 | |
| 19:00 | 09:00 | |
| 20:00 | 10:00 | |
| 21:00 | 11:00 | |
| 22:00 | 12:00 | |
| 23:00 | 13:00 |
Working hoursEarly or eveningNightWeekend
Plan a meeting: Tokyo and Uummannaq
More time differences with Tokyo
Questions
Asked about Tokyo and Uummannaq
What is the time difference between Tokyo and Uummannaq?
Uummannaq is 10 hours behind Tokyo. This holds until 24 October 2026; then Uummannaq is 11 hours behind Tokyo.
What is the best time for a call between Tokyo and Uummannaq?
No shared office hours. The least awkward windows, early or late for one side: Mon–Fri: 19:00–22:00 in Tokyo = 09:00–12:00 in Uummannaq · 3 h; Mon–Fri: 16:00–17:00 in Tokyo = 06:00–07:00 in Uummannaq · 1 h.
When does the time difference between Tokyo and Uummannaq change?
In the next 12 months it changes on: 24 October 2026 (−11 h); 28 March 2027 (−10 h).