Observatory log
Tokyo and Alert, compared
- 01Difference now
Alert is 13 hours behind Tokyo.
Tokyo: JST (UTC+9) · Alert: EDT (UTC−4)
Next changeFrom 1 November 2026: Alert is 14 hours behind Tokyo.
- 02Through 2026–2027
- 1 January 2026 – 8 March 2026−14 h
- 8 March 2026 – 1 November 2026−13 h
- 1 November 2026 – 14 March 2027−14 h
- 14 March 2027 – 7 November 2027−13 h
- 7 November 2027 – 31 December 2027−14 h
Difference of Alert 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
09:00–11:00 in Tokyo = 20:00–22:00 in Alert
No shared office hours: this is early or late for one side (Tue–Fri).
- 05Weekend
Tokyo: Saturday and Sunday
Alert: Saturday and Sunday
24 hours
A day in Tokyo, in Alert
| Tokyo | Alert | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 11:00Yesterday | |
| 01:00 | 12:00Yesterday | |
| 02:00 | 13:00Yesterday | |
| 03:00 | 14:00Yesterday | |
| 04:00 | 15:00Yesterday | |
| 05:00 | 16:00Yesterday | |
| 06:00 | 17:00Yesterday | |
| 07:00 | 18:00Yesterday | |
| 08:00 | 19:00Yesterday | |
| 09:00 | 20:00Yesterday | |
| 10:00 | 21:00Yesterday | |
| 11:00 | 22:00Yesterday | |
| 12:00 | 23:00Yesterday | |
| 13:00 | 00:00 | |
| 14:00 | 01:00 | |
| 15:00 | 02:00 | |
| 16:00 | 03:00 | |
| 17:00 | 04:00 | |
| 18:00 | 05:00 | |
| 19:00 | 06:00 | |
| 20:00 | 07:00 | |
| 21:00 | 08:00 | |
| 22:00 | 09:00 | |
| 23:00 | 10:00 |
Working hoursEarly or eveningNightWeekend
Plan a meeting: Tokyo and Alert
More time differences with Tokyo
Questions
Asked about Tokyo and Alert
What is the time difference between Tokyo and Alert?
Alert is 13 hours behind Tokyo. This holds until 1 November 2026; then Alert is 14 hours behind Tokyo.
What is the best time for a call between Tokyo and Alert?
No shared office hours. The least awkward windows, early or late for one side: Tue–Fri: 09:00–11:00 in Tokyo = 20:00–22:00 in Alert (yesterday) · 2 h.
When does the time difference between Tokyo and Alert change?
In the next 12 months it changes on: 1 November 2026 (−14 h); 14 March 2027 (−13 h).