Mountain Standard Time is UTC−07:00. Denver and most of the US Mountain zone use MST in winter and MDT in summer.
Detecting your timezone for a personal comparison…
Now
Mountain Time is split in practice. Arizona (America/Phoenix) stays on MST all year except for the Navajo Nation. This page uses America/Denver so the clock matches Colorado, Utah, New Mexico, and Alberta when they follow the US daylight-saving calendar. If you need Arizona time specifically, use the Phoenix city page.
The offset shown above is computed from America/Denver at page render time using Intl.DateTimeFormat. It can change when daylight saving starts or ends.
America/Denver observes daylight saving (MDT, UTC−06:00). Arizona generally does not.
Mountain Standard Time (MST) uses the IANA identifier America/Denver. Mountain Standard Time is UTC−07:00. Denver and most of the US Mountain zone use MST in winter and MDT in summer.
Right now Mountain Standard Time is UTC-06:00. The live abbreviation reported by the timezone database is MDT.
Daylight saving time is in effect. Standard time is labeled MST and daylight time is labeled MDT. Dates are taken from IANA data, not hardcoded on this site.
Use the converter with America/Denver as the source zone, or open the Time Zone Converter and pick a city that uses MST. Offsets update automatically when daylight saving begins or ends.