MDT — Mountain Daylight Time
MDT is Mountain Daylight Time, 6 hours behind UTC. It is a fixed offset: unlike a time zone, it does not change with the season — the zones that use it switch to a different abbreviation instead.
Current time in MDT
01:46
Sunday, 2 August 2026
MDT = UTC-6 · 6 hours behind UTC
Shown for 2 Aug 2026 07:46 UTC. The clock goes live as soon as scripts load.
UTC offset
UTC-6
Type
Daylight saving
Seasonal counterpart
MST
The letters the same zones use for the other half of the year
Meanings
1
Unambiguous
Is MDT in force right now?
A zone only carries this abbreviation for part of the year. This is which of them were on it at 2 Aug 2026 07:46 UTC; the list is re-derived against your own clock when scripts load.
On MDT now
- America/Denver — Denver
- America/Edmonton — Calgary
- America/Boise — Boise
Using a different abbreviation
- Every zone listed here was on MDT.
MDT alternates with MST across the year.
Writing “MDT” for a date in the other half of the year is the most common time zone mistake in meeting invitations.
Convert MDT to other time zones
City clocks reflect whatever their zone is doing; where a city observes daylight saving time, its difference from MDT changes twice a year. Use the time zone converter for a specific date.
Time zones and cities that use MDT
Mountain Daylight Time · UTC-6
Why MDT is not an identifier
MDT is shorthand, not a standard. There is no registry of time zone abbreviations, no authority that assigns them, and nothing preventing two regions from adopting the same three letters — which is what makes codes like IST and CST unusable without context.
For anything a machine will read — a calendar invitation, a database column, an API response — use the IANA identifier of the zone (America/Denver, for example) or an explicit UTC offset alongside the date. The identifier survives a change in the law; MDT and its 6 hours offset do not.
Abbreviations on the same clock
Frequently asked questions
What does MDT stand for?
MDT stands for Mountain Daylight Time. It is 6 hours behind UTC, written UTC-6.
What is MDT in UTC?
MDT is UTC-6. To convert an MDT time to UTC, add 6 hours.
What is the difference between MDT and MST?
MDT is the daylight saving form and MST the standard form of the same zones. The two are one hour apart and only one is ever in force at a time, so a recurring meeting written "MDT" shifts by an hour when the clocks change.
Which time zone should I use instead of MDT?
Use an IANA identifier — America/Denver, America/Edmonton and America/Boise for Mountain Daylight Time — or state the UTC offset with the date. Abbreviations are not identifiers: they are not unique, they are not registered anywhere, and half of them change with the season. Calendar software resolves this automatically when you pick a city rather than typing letters.