Observatory log
Tokyo and Atka, compared
- 01Difference now
Atka is 18 hours behind Tokyo.
Tokyo: JST (UTC+9) · Atka: HDT (UTC−9)
Next changeFrom 1 November 2026: Atka is 19 hours behind Tokyo.
- 02Through 2026–2027
- 1 January 2026 – 8 March 2026−19 h
- 8 March 2026 – 1 November 2026−18 h
- 1 November 2026 – 14 March 2027−19 h
- 14 March 2027 – 7 November 2027−18 h
- 7 November 2027 – 31 December 2027−19 h
Difference of Atka from Tokyo. It changes on the days either place changes its clocks (dates local to that place).
- 03Shared working hours
- Tue–Fri: 09:00–11:00 in Tokyo = 15:00–17:00 in Atka (yesterday) · 2 h
Counted as 09:00–17:00 local time on each place’s own working days, for the next seven days.
- 04Best time to meet
09:00–11:00 in Tokyo = 15:00–17:00 in Atka
Inside both working days (Tue–Fri).
- 05Weekend
Tokyo: Saturday and Sunday
Atka: Saturday and Sunday
24 hours
A day in Tokyo, in Atka
| Tokyo | Atka | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 06:00Yesterday | |
| 01:00 | 07:00Yesterday | |
| 02:00 | 08:00Yesterday | |
| 03:00 | 09:00Yesterday | |
| 04:00 | 10:00Yesterday | |
| 05:00 | 11:00Yesterday | |
| 06:00 | 12:00Yesterday | |
| 07:00 | 13:00Yesterday | |
| 08:00 | 14:00Yesterday | |
| 09:00 | 15:00Yesterday | |
| 10:00 | 16:00Yesterday | |
| 11:00 | 17:00Yesterday | |
| 12:00 | 18:00Yesterday | |
| 13:00 | 19:00Yesterday | |
| 14:00 | 20:00Yesterday | |
| 15:00 | 21:00Yesterday | |
| 16:00 | 22:00Yesterday | |
| 17:00 | 23:00Yesterday | |
| 18:00 | 00:00 | |
| 19:00 | 01:00 | |
| 20:00 | 02:00 | |
| 21:00 | 03:00 | |
| 22:00 | 04:00 | |
| 23:00 | 05:00 |
Working hoursEarly or eveningNightWeekend
Plan a meeting: Tokyo and Atka
More time differences with Tokyo
Questions
Asked about Tokyo and Atka
What is the time difference between Tokyo and Atka?
Atka is 18 hours behind Tokyo. This holds until 1 November 2026; then Atka is 19 hours behind Tokyo.
What is the best time for a call between Tokyo and Atka?
Inside both working days: Tue–Fri: 09:00–11:00 in Tokyo = 15:00–17:00 in Atka (yesterday) · 2 h.
When does the time difference between Tokyo and Atka change?
In the next 12 months it changes on: 1 November 2026 (−19 h); 14 March 2027 (−18 h).