Rio de Janeiro to Great Falls, MT: time difference
Great Falls, MT is 3 h behind Rio de Janeiro. Live clocks for both, the working hours they share, and how each one sits against your own time.
Your time
One day, 2 clocks
Drag along the band to read any hour in every place at once.
Rio de Janeiro 02:03 2:03 AM Great Falls, MT 23:03 11:03 PM You –:–
02:03 2:03 AM
Brasilia Standard Time · UTC-3
☀️ 05:25 · 🌙 17:56
23:03 11:03 PM
Mountain Daylight Time · UTC-6
☀️ 07:37 · 🌙 18:48
·
−3 h
Great Falls, MT is 3 h behind Rio de Janeiro.
When you, Rio de Janeiro and Great Falls, MT are all at the desk
Pick the working hours below – the window every location shares appears once your time zone is known.
Working hours
🇧🇷 Rio de Janeiro
0 12 AM 1 1 AM 2 2 AM 3 3 AM 4 4 AM 5 5 AM 6 6 AM 7 7 AM 8 8 AM 9 9 AM 10 10 AM 11 11 AM 12 12 PM 13 1 PM 14 2 PM 15 3 PM 16 4 PM 17 5 PM 18 6 PM 19 7 PM 20 8 PM 21 9 PM 22 10 PM 23 11 PM
🇺🇸 Great Falls, MT
21 9 PM 22 10 PM 23 11 PM 0 12 AM 1 1 AM 2 2 AM 3 3 AM 4 4 AM 5 5 AM 6 6 AM 7 7 AM 8 8 AM 9 9 AM 10 10 AM 11 11 AM 12 12 PM 13 1 PM 14 2 PM 15 3 PM 16 4 PM 17 5 PM 18 6 PM 19 7 PM 20 8 PM
📍 Your time
- Asleep
- Early
- Working hours
- Evening
- Both working
- Right now
Time zones side by side
| Detail | 🇧🇷 Rio de Janeiro | 🇺🇸 Great Falls, MT |
|---|---|---|
| Local time | 02:03 | 23:03 |
| Local date | Sunday, October 11, 2026 | Saturday, October 10, 2026 |
| Time zone | Brasilia Standard Time | Mountain Daylight Time |
| UTC offset | UTC-3 | UTC-6 |
| Offset from Rio de Janeiro | — | −3 h |
| IANA zone | America/Sao Paulo | America/Denver |
| Daylight saving | Not observed | On summer time → UTC-7, Nov 1, 01:00 |
| Sunrise | 05:25 | 07:37 |
| Sunset | 17:56 | 18:48 |
| Daylight | 12 h 31 min | 11 h 11 min |
| People on this clock | 6,211,223 | 60,442 |
Compare Rio de Janeiro with another city
More comparisons with Rio de Janeiro: the time zones next to it and the far side of the clock.
Nearby time zones
Big time differences
Rio de Janeiro and Great Falls, MT: common questions
How many hours behind Rio de Janeiro is Great Falls, MT?
The clocks in Great Falls are 3 hours behind those in Rio de Janeiro (UTC−6 and UTC−3).
What time is it in Great Falls, MT, when it is 9:00 AM in Rio de Janeiro?
When it is 9:00 AM in Rio de Janeiro, it is 6:00 AM in Great Falls.
What time is it in Great Falls, MT, at the end of the working day in Rio de Janeiro?
The working day in Rio de Janeiro ends at 6:00 PM; in Great Falls it is 3:00 PM at that moment.
When is a good time to call Great Falls, MT, from Rio de Janeiro?
Between 12:00 PM and 6:00 PM in Rio de Janeiro – that is 9:00 AM to 3:00 PM in Great Falls – both places are within working hours (9:00 AM–6:00 PM).
When is it still the previous day in Great Falls, MT?
Until 3:00 AM in Rio de Janeiro it is still the previous day in Great Falls. The other way round, from 9:00 PM in Great Falls it is already the next day in Rio de Janeiro.
Does the time difference between Rio de Janeiro and Great Falls, MT, change?
Yes. The clocks change only in Great Falls. From November 1, 2026, Great Falls will be 4 hours behind Rio de Janeiro.
