Current time in Boulder, United States

The current local time in Boulder is shown below. Boulder observes MST in winter and MDT during daylight saving time.

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🇺🇸 BoulderMST

What's the daylight saving status?

Currently in MDT (daylight saving)
Clocks go back to MST on Sunday 1 November 2026

When are sunrise & sunset today?

Sunrise
05:37
Sunset
20:21
Day length
14h 44m
Solar noon
12:59

What are the timezone facts?

Timezone
America/Denver
Standard abbreviation
MST
DST abbreviation
MDT
Observes daylight saving
Yes
Country
🇺🇸 United States
Business hours
09:00 – 17:00 local

What's the timezone history of Boulder?

Boulder uses Mountain Time and observes federal DST. The city's high-altitude position at the foot of the Rockies places it close to the line where the Mountain Time zone's western edge meets the desert states. The Wyoming border 80 kilometres north marks no zone change; Mountain Time extends through most of the Rocky Mountain corridor. The federal DST decision-making takes on local relevance here through the National Institute of Standards and Technology atomic-clock facility in Boulder, which provides the reference time signal for the entire US.

What are the working hours in Boulder?

Boulder's working economy is dominated by the University of Colorado (the largest employer with around 7,000 staff and 35,000 students), the substantial federal-laboratory cluster including NIST, NOAA, and the National Center for Atmospheric Research, and a long-established outdoor and natural-products industry (Celestial Seasonings, IBM Boulder, Crocs). Office hours run 09:00 to 17:30 in conventional sectors. The Bolder Boulder 10-kilometre race on Memorial Day attracts around 50,000 runners and is the city's largest annual sporting event.

Where is Boulder?

Boulder sits at the eastern foot of the Rocky Mountains in north-central Colorado, around 45 kilometres north-west of Denver. The city proper holds around 105,000 residents, with the wider Boulder County at around 330,000. The geography combines the city plain at around 1,650 metres elevation with the Flatirons sandstone formations rising sharply on the western edge to over 2,400 metres. The Boulder Creek runs east through the city, draining the high country down toward the South Platte River. The city's growth limits and open-space preservation produce a sharp boundary between urban and protected land.