Observatory log
Hong Kong and Boulder, compared
- 01Difference now
Boulder is 14 hours behind Hong Kong.
Hong Kong: HKT (UTC+8) · Boulder: MDT (UTC−6)
Next changeFrom 1 November 2026: Boulder is 15 hours behind Hong Kong.
- 02Through 2026–2027
- 1 January 2026 – 8 March 2026−15 h
- 8 March 2026 – 1 November 2026−14 h
- 1 November 2026 – 14 March 2027−15 h
- 14 March 2027 – 7 November 2027−14 h
- 7 November 2027 – 31 December 2027−15 h
Difference of Boulder from Hong Kong. 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
09:00–12:00 in Hong Kong = 19:00–22:00 in Boulder
No shared office hours: this is early or late for one side (Tue–Fri).
Also possible: Tue–Fri: 06:00–07:00 in Hong Kong = 16:00–17:00 in Boulder (yesterday) · 1 h.
- 05Weekend
Hong Kong: Saturday and Sunday
Boulder: Saturday and Sunday
24 hours
A day in Hong Kong, in Boulder
| Hong Kong | Boulder | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 10:00Yesterday | |
| 01:00 | 11:00Yesterday | |
| 02:00 | 12:00Yesterday | |
| 03:00 | 13:00Yesterday | |
| 04:00 | 14:00Yesterday | |
| 05:00 | 15:00Yesterday | |
| 06:00 | 16:00Yesterday | |
| 07:00 | 17:00Yesterday | |
| 08:00 | 18:00Yesterday | |
| 09:00 | 19:00Yesterday | |
| 10:00 | 20:00Yesterday | |
| 11:00 | 21:00Yesterday | |
| 12:00 | 22:00Yesterday | |
| 13:00 | 23:00Yesterday | |
| 14:00 | 00:00 | |
| 15:00 | 01:00 | |
| 16:00 | 02:00 | |
| 17:00 | 03:00 | |
| 18:00 | 04:00 | |
| 19:00 | 05:00 | |
| 20:00 | 06:00 | |
| 21:00 | 07:00 | |
| 22:00 | 08:00 | |
| 23:00 | 09:00 |
Working hoursEarly or eveningNightWeekend
Questions
Asked about Hong Kong and Boulder
What is the time difference between Hong Kong and Boulder?
Boulder is 14 hours behind Hong Kong. This holds until 1 November 2026; then Boulder is 15 hours behind Hong Kong.
What is the best time for a call between Hong Kong and Boulder?
No shared office hours. The least awkward windows, early or late for one side: Tue–Fri: 09:00–12:00 in Hong Kong = 19:00–22:00 in Boulder (yesterday) · 3 h; Tue–Fri: 06:00–07:00 in Hong Kong = 16:00–17:00 in Boulder (yesterday) · 1 h.
When does the time difference between Hong Kong and Boulder change?
In the next 12 months it changes on: 1 November 2026 (−15 h); 14 March 2027 (−14 h).