Mountain Daylight Time (MDT)
Mountain Daylight Time (MDT) is UTC−6. It is the daylight saving (summer) time of US and Canadian Mountain zone during daylight saving time (not Arizona); in winter the area returns to MST (UTC−7).
MDT is not in force right now – the zone is currently on MST (UTC−7).
Convert MDT
Where MDT is used
US and Canadian Mountain zone during daylight saving time (not Arizona).
Major cities on America/Denver
MDT and daylight saving time
The next change is on 14 March 2027 at 01:59 local time: clocks go forward one hour, from MST (UTC−7) to MDT (UTC−6).
MDT FAQ
What is MDT?
Mountain Daylight Time (MDT) is UTC−6. It is the daylight saving (summer) time of US and Canadian Mountain zone during daylight saving time (not Arizona); in winter the area returns to MST (UTC−7).
What is the current MDT time?
MDT is UTC−6. The live clock on this page shows the current Mountain Daylight Time time, updated every second.
What is the difference between MDT and MST?
MST is one hour behind MDT. MDT is used during daylight saving time; MST is the standard time.
Is MDT the same as MT?
MT (Mountain Time) is the year-round name. MDT is the exact name used in summer. People often write MT when they mean whichever one is in force today.
Which countries use MDT?
MDT is used in US and Canadian Mountain zone during daylight saving time (not Arizona).
Updated 6 November 2026. Time zone data: IANA tz database.