Buenos Aires to Boulder, CO: time difference
Boulder, CO is 3 h behind Buenos Aires. 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.
Buenos Aires 10:17 10:17 AM Boulder, CO 07:17 7:17 AM You –:–
10:17 10:17 AM
Argentina Standard Time · UTC-3
☀️ 06:06 · 🌙 19:12
07:17 7:17 AM
Mountain Daylight Time · UTC-6
☀️ 07:19 · 🌙 18:17
·
−3 h
Boulder, CO is 3 h behind Buenos Aires.
When you, Buenos Aires and Boulder, CO are all at the desk
Pick the working hours below – the window every location shares appears once your time zone is known.
Working hours
🇦🇷 Buenos Aires
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
🇺🇸 Boulder, CO
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 | 🇦🇷 Buenos Aires | 🇺🇸 Boulder, CO |
|---|---|---|
| Local time | 10:17 | 07:17 |
| Local date | Tuesday, October 20, 2026 | Tuesday, October 20, 2026 |
| Time zone | Argentina Standard Time | Mountain Daylight Time |
| UTC offset | UTC-3 | UTC-6 |
| Offset from Buenos Aires | — | −3 h |
| IANA zone | America/Argentina/Buenos Aires | America/Denver |
| Daylight saving | Not observed | On summer time → UTC-7, Nov 1, 01:00 |
| Sunrise | 06:06 | 07:19 |
| Sunset | 19:12 | 18:17 |
| Daylight | 13 h 6 min | 10 h 58 min |
| People on this clock | 2,891,082 | 106,803 |
Compare Buenos Aires with another city
More comparisons with Buenos Aires: the time zones next to it and the far side of the clock.
Nearby time zones
Big time differences
Buenos Aires and Boulder, CO: common questions
How many hours behind Buenos Aires is Boulder, CO?
The clocks in Boulder are 3 hours behind those in Buenos Aires (UTC−6 and UTC−3).
If it is 9:00 AM in Buenos Aires, what time is it in Boulder, CO?
At 9:00 AM in Buenos Aires, clocks in Boulder show 6:00 AM.
What time is it in Boulder, CO, at the end of the working day in Buenos Aires?
The working day in Buenos Aires ends at 6:00 PM; in Boulder it is 3:00 PM at that moment.
When is a good time to call Boulder, CO, from Buenos Aires?
Between 12:00 PM and 6:00 PM in Buenos Aires – that is 9:00 AM to 3:00 PM in Boulder – both places are within working hours (9:00 AM–6:00 PM).
When is it still the previous day in Boulder, CO?
Until 3:00 AM in Buenos Aires it is still the previous day in Boulder. The other way round, from 9:00 PM in Boulder it is already the next day in Buenos Aires.
Is the time difference between Buenos Aires and Boulder, CO, the same all year?
No. Only Boulder switches to summer time, so the gap changes twice a year. From November 1, 2026, Boulder will be 4 hours behind Buenos Aires.
