- Type a city, a country or a zone such as “CET” or “Tokyo”.
Current local time in Boulder, United States
America/Denver
Observatory log
Boulder, observed
- 01Time zone
Mountain Daylight Time
MDT · UTC−6 · IANA
America/Denver- 02Daylight saving
Daylight saving time is in effect (MDT)
Last changeSunday, 8 March 2026 at 02:00: clocks go forward 1 hour to 03:00 (MST → MDT).
Next changeSunday, 1 November 2026 at 02:00: clocks go back 1 hour to 01:00 (MDT → MST).
- 03Sun today
- Sunrise07:10Sunset18:22Day length11 h 12 minSolar noon12:46
MoonWaxing crescent, 16% lit
Golden hour06:54–07:47 · 17:46–18:39
- 04Working hours
Counted as 09:00–17:00 local; the weekend in United States is Saturday and Sunday.
- 05Best time to call
- 06Time zones in United States
- HonoluluHST
- AtkaHDT
- AnchorageAKDT
- JuneauAKDT
- MetlakatlaAKDT
- NomeAKDT
- KetchikanAKDT
- YakutatAKDT
- Los AngelesPDT
- PhoenixMST
- BoiseMDT
- DenverMDT
and 17 more zones.
- 07Also on this clock
- 08Coordinates
40.04° N, 105.25° W · Colorado
Differences
Boulder and the world
| City | Local time | Difference from BoulderDiff. |
|---|---|---|
 London | +7 h | |
 New York | +2 h | |
| Los Angeles | −1 h | |
| Chicago | +1 h | |
 São Paulo | +3 h | |
 Paris | +8 h | |
 Dubai | +10 h | |
 Mumbai | +11 h 30 min | |
 Singapore | +14 h | |
 Hong Kong | +14 h | |
 Tokyo | +15 h |
More cities in United States
Questions
Asked about Boulder
What time zone is Boulder in?
Boulder uses Mountain Daylight Time (MDT), UTC−6. Its IANA time-zone ID is America/Denver.
Does Boulder use daylight saving time?
Yes. The next change is on Sunday, 1 November 2026 at 02:00: clocks go back 1 hour to 01:00 (MDT → MST).
When does the sun rise and set in Boulder today?
Today in Boulder the sun rises at 07:10 and sets at 18:22, giving 11 h 12 min of daylight.