Observatory log
Chicago and Son Tay, compared
- 01Difference now
Son Tay is 12 hours ahead of Chicago.
Chicago: CDT (UTC−5) · Son Tay: UTC+7 (UTC+7)
Next changeFrom 1 November 2026: Son Tay is 13 hours ahead of Chicago.
- 02Through 2026–2027
- 1 January 2026 – 8 March 2026+13 h
- 8 March 2026 – 1 November 2026+12 h
- 1 November 2026 – 14 March 2027+13 h
- 14 March 2027 – 7 November 2027+12 h
- 7 November 2027 – 31 December 2027+13 h
Difference of Son Tay from Chicago. 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
09:00–10:00 in Chicago = 21:00–22:00 in Son Tay
No shared office hours: this is early or late for one side (Mon–Fri).
Also possible: Mon–Thu: 21:00–22:00 in Chicago = 09:00–10:00 in Son Tay (tomorrow) · 1 h.
- 05Weekend
Chicago: Saturday and Sunday
Son Tay: Saturday and Sunday
24 hours
A day in Chicago, in Son Tay
| Chicago | Son Tay | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 12:00 | |
| 01:00 | 13:00 | |
| 02:00 | 14:00 | |
| 03:00 | 15:00 | |
| 04:00 | 16:00 | |
| 05:00 | 17:00 | |
| 06:00 | 18:00 | |
| 07:00 | 19:00 | |
| 08:00 | 20:00 | |
| 09:00 | 21:00 | |
| 10:00 | 22:00 | |
| 11:00 | 23:00 | |
| 12:00 | 00:00Tomorrow | |
| 13:00 | 01:00Tomorrow | |
| 14:00 | 02:00Tomorrow | |
| 15:00 | 03:00Tomorrow | |
| 16:00 | 04:00Tomorrow | |
| 17:00 | 05:00Tomorrow | |
| 18:00 | 06:00Tomorrow | |
| 19:00 | 07:00Tomorrow | |
| 20:00 | 08:00Tomorrow | |
| 21:00 | 09:00Tomorrow | |
| 22:00 | 10:00Tomorrow | |
| 23:00 | 11:00Tomorrow |
Working hoursEarly or eveningNightWeekend
Plan a meeting: Chicago and Son Tay
More time differences with Chicago
Questions
Asked about Chicago and Son Tay
What is the time difference between Chicago and Son Tay?
Son Tay is 12 hours ahead of Chicago. This holds until 1 November 2026; then Son Tay is 13 hours ahead of Chicago.
What is the best time for a call between Chicago and Son Tay?
No shared office hours. The least awkward windows, early or late for one side: Mon–Fri: 09:00–10:00 in Chicago = 21:00–22:00 in Son Tay · 1 h; Mon–Thu: 21:00–22:00 in Chicago = 09:00–10:00 in Son Tay (tomorrow) · 1 h.
When does the time difference between Chicago and Son Tay change?
In the next 12 months it changes on: 1 November 2026 (+13 h); 14 March 2027 (+12 h).