Observatory log
Mumbai and Boulder, compared
- 01Difference now
Boulder is 11 hours 30 minutes behind Mumbai.
Mumbai: IST (UTC+5:30) · Boulder: MDT (UTC−6)
Next changeFrom 1 November 2026: Boulder is 12 hours 30 minutes behind Mumbai.
- 02Through 2026–2027
- 1 January 2026 – 8 March 2026−12 h 30 min
- 8 March 2026 – 1 November 2026−11 h 30 min
- 1 November 2026 – 14 March 2027−12 h 30 min
- 14 March 2027 – 7 November 2027−11 h 30 min
- 7 November 2027 – 31 December 2027−12 h 30 min
Difference of Boulder from Mumbai. 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
20:30–22:00 in Mumbai = 09:00–10:30 in Boulder
No shared office hours: this is early or late for one side (Mon–Fri).
Also possible: Tue–Fri: 09:00–09:30 in Mumbai = 21:30–22:00 in Boulder (yesterday) · 30 min.
- 05Weekend
Mumbai: Saturday and Sunday
Boulder: Saturday and Sunday
24 hours
A day in Mumbai, in Boulder
| Mumbai | Boulder | Working hours, evening, night or weekend in each place |
|---|---|---|
| 00:00 | 12:30Yesterday | |
| 01:00 | 13:30Yesterday | |
| 02:00 | 14:30Yesterday | |
| 03:00 | 15:30Yesterday | |
| 04:00 | 16:30Yesterday | |
| 05:00 | 17:30Yesterday | |
| 06:00 | 18:30Yesterday | |
| 07:00 | 19:30Yesterday | |
| 08:00 | 20:30Yesterday | |
| 09:00 | 21:30Yesterday | |
| 10:00 | 22:30Yesterday | |
| 11:00 | 23:30Yesterday | |
| 12:00 | 00:30 | |
| 13:00 | 01:30 | |
| 14:00 | 02:30 | |
| 15:00 | 03:30 | |
| 16:00 | 04:30 | |
| 17:00 | 05:30 | |
| 18:00 | 06:30 | |
| 19:00 | 07:30 | |
| 20:00 | 08:30 | |
| 21:00 | 09:30 | |
| 22:00 | 10:30 | |
| 23:00 | 11:30 |
Working hoursEarly or eveningNightWeekend
Plan a meeting: Mumbai and Boulder
More time differences with Mumbai
Questions
Asked about Mumbai and Boulder
What is the time difference between Mumbai and Boulder?
Boulder is 11 hours 30 minutes behind Mumbai. This holds until 1 November 2026; then Boulder is 12 hours 30 minutes behind Mumbai.
What is the best time for a call between Mumbai and Boulder?
No shared office hours. The least awkward windows, early or late for one side: Mon–Fri: 20:30–22:00 in Mumbai = 09:00–10:30 in Boulder · 1 h 30 min; Tue–Fri: 09:00–09:30 in Mumbai = 21:30–22:00 in Boulder (yesterday) · 30 min.
When does the time difference between Mumbai and Boulder change?
In the next 12 months it changes on: 1 November 2026 (−12 h 30 min); 14 March 2027 (−11 h 30 min).