Mountain Standard Time

Frequently asked questions

Common questions about MST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].

Why are many MST zones on daylight time for most of the year?

Zones like Denver, Boise, Cambridge Bay, and Ciudad Juárez follow the spring-forward/fall-back schedule, so for about eight months a year, much of the region is actually on MDT, not MST.

Are there any MST zones that never change their clocks?

Yes: Phoenix in Arizona and most of British Columbia, including Vancouver, Creston, Dawson Creek, and Fort Nelson, stay on UTC-07:00 all year. Edmonton and Inuvik stopped changing clocks too, but they stay on UTC-06:00, an hour ahead of MST.

Does Mexico follow the same DST rules as the U.S. and Canada in this region?

Mostly—but not perfectly. Ciudad Juárez follows U.S. DST dates. Most of Mexico abolished daylight saving in 2022; only a few other border areas, such as Tijuana and Matamoros, still change clocks on U.S. dates.

How do I avoid confusion when scheduling across MST zones?

Use city-based labels (e.g., Denver vs. Creston) and always check whether DST is active; small towns can be an hour apart even within the same region.

What’s the time difference between Boise and Edmonton?

None from March to November, when both are on UTC-06:00. In winter Boise falls back to UTC-07:00 while Edmonton stays on UTC-06:00, because Alberta ended seasonal clock changes in 2026, so from November to March Edmonton is an hour ahead.

Is Mountain Time the same everywhere in North America?

No. Unlike Eastern or Central time, Mountain’s patchwork of DST rules and local exceptions—especially in British Columbia and northern border areas—makes it a bit more unpredictable.

When does MST officially “start” again after daylight saving ends?

In most DST-observing zones, you’ll see the clock roll back on the first Sunday of November at 2 a.m. local time, flipping from UTC-06:00 (MDT) to UTC-07:00 (MST).

Can two cities in MST be an hour apart?

Yes. From March to November, the zones that skip daylight saving (Phoenix and most of British Columbia, including Vancouver, Creston, Dawson Creek, and Fort Nelson) stay on UTC-07:00 while the rest of the region is on UTC-06:00, so a one-hour gap exists within the same region. Edmonton and Inuvik stay on UTC-06:00 in winter too, since Alberta and the Northwest Territories ended seasonal clock changes in 2026.