GMT to MDT Converter
The United Kingdom is on summer time: BST (UTC+1) until Sun, Oct 25.
Iceland and Ghana stay on GMT (UTC+0).
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
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Selected conversion
12:00 pm12:00 GMT (UTC+0), Oct 16, 2026 = 6:00 am06:00 MDT (UTC-6), Oct 16, 2026
GMT is 6 hours ahead of MDT.
GMT and MDT examples
These examples always use GMT (UTC+0) and MDT (UTC-6). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
GMT is 6 hours ahead of MDT.
How the time difference changes
For most of the year, GMT is 6 hours ahead of MDT. From Nov 1, 2026 to Mar 14, 2027, GMT is 7 hours ahead of MST.
For most of the year, working hours of 9:00 am to 6:00 pm in GMT correspond to 3:00 am to 12:00 pm in MDT. At other times of the year, working hours of 9:00 am to 6:00 pm in GMT correspond to 2:00 am to 11:00 am in MST.For most of the year, working hours of 09:00 to 18:00 in GMT correspond to 03:00 to 12:00 in MDT. At other times of the year, working hours of 09:00 to 18:00 in GMT correspond to 02:00 to 11:00 in MST.
Compare GMT time with MDT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Greenwich Mean Time is 6 hours ahead of Mountain Daylight Time.
12:00 pm12:00 in GMT is 6:00 am06:00 in MDT
GMT to MDT call time
Best time for a conference call or a meeting is between 3pm-6pm15:00-18:00 in GMT which corresponds to 9am-12pm09:00-12:00 in MDT
12:00 pm12:00 Greenwich Mean Time (GMT). Offset UTC 0:00 hours
6:00 am06:00 Mountain Daylight Time (MDT). Offset UTC -6:00 hours
12:00 pm12:00 GMT / 6:00 am06:00 MDT
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
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Greenwich Mean Time
Offset: GMT is the same as Greenwich Mean Time (GMT).
Countries using this time zone: Antarctica, Burkina Faso, Gambia, Ghana, Greenland, Guernsey, Guinea, Guinea-Bissau, Iceland, Ireland, Isle of Man, Ivory Coast, Jersey, Liberia, Mali, Mauritania, Morocco, Saint Helena, São Tomé and Príncipe, Senegal, Sierra Leone, Togo, United Kingdom, Western Sahara
Principal Cities: The largest city in the GMT time zone is London in the United Kingdom, with about 8.962 million people. Other major cities in this time zone include Abidjan, Bamako, Casablanca, Dakar.
Greenwich Mean Time (GMT) originally referred to the mean solar time at the Royal Observatory in Greenwich, London. It is now often used to refer to Coordinated Universal Time (UTC) when this is viewed as a time zone, and in casual use the two are the same. In the military, GMT is known as Zulu time. Greenwich Mean Time was the same as Universal Time (UT), a standard astronomical concept used in many technical fields, until the introduction of UTC in 1972.
Today the lighter areas are on UTC+1 (British Summer Time, Irish Standard Time).
GMT representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for GMT
- Z - short form of 'Zulu'
- Africa/Abidjan
- Africa/Accra
- Africa/Bamako
- Africa/Banjul
- Africa/Bissau
- Africa/Conakry
- Africa/Dakar
- Africa/Freetown
- Africa/Lome
- Africa/Monrovia
- Africa/Nouakchott
- Africa/Ouagadougou
- Africa/Sao_Tome
- Africa/Timbuktu
- America/Danmarkshavn
- Atlantic/Reykjavik
- Atlantic/St_Helena
- Eire
- Etc/GMT
- Etc/GMT+0
- Etc/GMT-0
- Etc/GMT0
- Etc/Greenwich
- Europe/Belfast
- Europe/Dublin
- Europe/Guernsey
- Europe/Isle_of_Man
- Europe/Jersey
- Europe/London
- GB
- GB-Eire
- GMT
- GMT+0
- GMT-0
- GMT0
- Greenwich
- Iceland
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Coordinated Universal Time
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone
Mountain Daylight Time
Offset: MDT is 6 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Canada, Mexico, United States
Principal Cities: The largest city in the MDT time zone is Ciudad Juárez in Mexico, with about 1.512 million people. Other major cities in this time zone include Denver, El Paso, Albuquerque, Colorado Springs.
French: HAR - Heure Avancée des Rocheuses
Spanish: MT - Zona Pacífico
Today all shaded areas are on MDT.
Daylight Saving: Mountain Daylight Time (MDT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Mountain Standard Time (MST).
Start: Mountain Daylight Time (MDT) started on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.
End: Mountain Daylight Time (MDT) ends on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the first Sunday of November.
See USA daylight saving time and upcoming clock changes worldwide.
MDT representations, usage and related time zones
- -06 - basic short
- -0600 - basic
- -06:00 - extended
- -0600 - sign character (-) followed by a four digit time providing hours (06) and minutes (00) of the offset. Indicates an offset of six hours to the west of the zero meridian.
- Sierra - Military abbreviation for MDT
- S - short form of 'Sierra'
- America/Boise
- America/Cambridge_Bay
- America/Ciudad_Juarez
- America/Denver
- America/Edmonton
- America/Inuvik
- America/Shiprock
- America/Yellowknife
- Canada/Mountain
- MST7MDT
- Navajo
- US/Mountain
- CST - Central Standard Time
- CT - Central Time
- MDT - Mountain Daylight Time
- EAST - Easter Island Standard Time
- GALT - Galapagos Time
- S - Sierra Time Zone