Great Falls, MT to Rio de Janeiro: time difference
Rio de Janeiro is 3 h ahead of Great Falls, MT. Live clocks for both, the working hours they share, and how each one sits against your own time.
+3 h
Your time
One day, 2 clocks
Drag along the band to read any hour in every place at once.
Great Falls, MT 22:08 10:08 PM Rio de Janeiro 01:08 1:08 AM You –:–
22:08 10:08 PM
Mountain Daylight Time · UTC-6
☀️ 07:37 · 🌙 18:48
01:08 1:08 AM
Brasilia Standard Time · UTC-3
☀️ 05:25 · 🌙 17:56
·
+3 h
Rio de Janeiro is 3 h ahead of Great Falls, MT.
When you, Great Falls, MT and Rio de Janeiro are all at the desk
Pick the working hours below – the window every location shares appears once your time zone is known.
Working hours
🇺🇸 Great Falls, MT
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
🇧🇷 Rio de Janeiro
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 0 12 AM 1 1 AM 2 2 AM
📍 Your time
- Asleep
- Early
- Working hours
- Evening
- Both working
- Right now
Time zones side by side
| Detail | 🇺🇸 Great Falls, MT | 🇧🇷 Rio de Janeiro |
|---|---|---|
| Local time | 22:08 | 01:08 |
| Local date | Saturday, October 10, 2026 | Sunday, October 11, 2026 |
| Time zone | Mountain Daylight Time | Brasilia Standard Time |
| UTC offset | UTC-6 | UTC-3 |
| Offset from Great Falls, MT | — | +3 h |
| IANA zone | America/Denver | America/Sao Paulo |
| Daylight saving | On summer time → UTC-7, Nov 1, 01:00 | Not observed |
| Sunrise | 07:37 | 05:25 |
| Sunset | 18:48 | 17:56 |
| Daylight | 11 h 11 min | 12 h 31 min |
| People on this clock | 60,442 | 6,211,223 |
Compare Great Falls, MT with another city
More comparisons with Great Falls, MT: the time zones next to it and the far side of the clock.
Nearby time zones
Big time differences
Great Falls, MT and Rio de Janeiro: common questions
What is the time difference between Great Falls, MT, and Rio de Janeiro?
Rio de Janeiro is 3 hours ahead: it uses UTC−3, while Great Falls is on UTC−6.
What time is it in Rio de Janeiro at the start of the working day in Great Falls, MT?
The working day in Great Falls starts at 9:00 AM; in Rio de Janeiro it is 12:00 PM at that moment.
If it is 6:00 PM in Great Falls, MT, what time is it in Rio de Janeiro?
At 6:00 PM in Great Falls, clocks in Rio de Janeiro show 9:00 PM.
Is there a time when both Great Falls, MT, and Rio de Janeiro are at work?
Yes: from 9:00 AM to 3:00 PM in Great Falls (12:00 PM to 6:00 PM in Rio de Janeiro), the working days (9:00 AM–6:00 PM) overlap.
When is it already the next day in Rio de Janeiro?
From 9:00 PM in Great Falls, MT, it is already the next day in Rio de Janeiro. The other way round, until 3:00 AM in Rio de Janeiro it is still the previous day in Great Falls.
Is the time difference between Great Falls, MT, and Rio de Janeiro the same all year?
No. Only Great Falls switches to summer time, so the gap changes twice a year. From November 1, 2026, Rio de Janeiro will be 4 hours ahead of Great Falls.
