Updating current time…
MST/MDT
12am
3am
6am
9am
12pm
3pm
6pm
9pm
Mountain Time is on standard time: MST (UTC−7) until Sun, Mar 14, 2027.
ACDT
UTC+10:30
tomorrow (next day)
17h 30m ahead
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

9:00 am09:00 MST (UTC-7), Nov 1, 2026 = 2:30 am02:30 ACDT (UTC+10:30), Nov 2, 2026

MST is 17 hours and 30 minutes behind ACDT.

MDT and ACDT examples

These examples always use MDT (UTC-6) and ACDT (UTC+10:30). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

MDT is 16 hours and 30 minutes behind ACDT.

How the time difference changes

Depending on seasonal clock changes, MDT is 15 hours and 30 minutes behind ACST, MDT is 16 hours and 30 minutes behind ACDT, or MST is 17 hours and 30 minutes behind ACDT.

Depending on seasonal clock changes, working hours of 9:00 am to 6:00 pm in MDT correspond to 12:30 am (next day) to 9:30 am (next day) in ACST, working hours of 9:00 am to 6:00 pm in MDT correspond to 1:30 am (next day) to 10:30 am (next day) in ACDT, or working hours of 9:00 am to 6:00 pm in MST correspond to 2:30 am (next day) to 11:30 am (next day) in ACDT.Depending on seasonal clock changes, working hours of 09:00 to 18:00 in MDT correspond to 00:30 (next day) to 09:30 (next day) in ACST, working hours of 09:00 to 18:00 in MDT correspond to 01:30 (next day) to 10:30 (next day) in ACDT, or working hours of 09:00 to 18:00 in MST correspond to 02:30 (next day) to 11:30 (next day) in ACDT.

Compare MDT time with ACDT time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Mountain Standard Time is 17 hours and 30 minutes behind Australian Central Daylight Time.
9:00 am09:00 in MST is 2:30 am02:30 in ACDT

MST to ACDT call time
Best time for a conference call or a meeting is between 3:30pm-6pm15:30-18:00 in MST which corresponds to 9am-11:30am09:00-11:30 in ACDT (next day)

9:00 am09:00 Mountain Standard Time (MST). Offset UTC -7:00 hours
2:30 am02:30 Australian Central Daylight Time (ACDT). Offset UTC +10:30 hours

9:00 am09:00 MST / 2:30 am02:30 ACDT

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.

Hourly time comparison
MSTACDT
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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

Map of the areas on Mountain Daylight Time (MDT)
MDT part of the year

Today the shaded areas are on UTC−7 (MST).

Daylight Saving: Mountain Daylight Time (MDT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Mountain Standard Time (MST).

123456789101112End: Mountain Daylight Time (MDT) ended on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks were 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.

123456789101112Start: Mountain Daylight Time (MDT) starts on Sunday, March 14, 2027 at 2:00 am02:00 local time and clocks are set one hour forward to Sunday, March 14, 2027, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.

See USA daylight saving time and upcoming clock changes worldwide.

MDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -06 - basic short
  • -0600 - basic
  • -06:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -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.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Sierra - Military abbreviation for MDT
  • S - short form of 'Sierra'
IANA/Olson: Reflects MDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Boise
  • America/Cambridge_Bay
  • America/Ciudad_Juarez
  • America/Denver
  • America/Edmonton
  • America/Inuvik
  • America/Shiprock
  • America/Yellowknife
  • Canada/Mountain
  • MST7MDT
  • Navajo
  • US/Mountain
Time zones with the GMT -6 offset:
  • CST - Central Standard Time
  • CT - Central Time
  • MDT - Mountain Daylight Time
  • EAST - Easter Island Standard Time
  • GALT - Galapagos Time
  • S - Sierra Time Zone

Australian Central Daylight Time

Offset: ACDT is 10 hours and 30 minutes ahead of Greenwich Mean Time (GMT).

Countries using this time zone: Australia

Principal Cities: The largest city in the ACDT time zone is Adelaide in Australia, with about 1.469 million people. Other major cities in this time zone include Mount Gambier, Mount Barker, Whyalla, Gawler.

Map of the areas on Australian Central Daylight Time (ACDT)
ACDT part of the year

Today all shaded areas are on ACDT.

Daylight Saving: Australian Central Daylight Time (ACDT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Australian Central Standard Time (ACST).

123456789101112Start: Australian Central Daylight Time (ACDT) started on Sunday, October 4, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, October 4, 2026, 3:00 am03:00. Daylight saving starts annually on the first Sunday of October.

123456789101112End: Australian Central Daylight Time (ACDT) ends on Sunday, April 4, 2027 at 3:00 am03:00 local time and clocks are set one hour back to Sunday, April 4, 2027, 2:00 am02:00 local standard time instead. Daylight saving ends annually on the first Sunday of April.

See Australia daylight saving time and upcoming clock changes worldwide.

ACDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +1030 - basic
  • +10:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +1030 - sign character (+) followed by a four digit time providing hours (10) and minutes (30) of the offset. Indicates an offset of ten hours and thirty minutes to the east of the zero meridian.
IANA/Olson: Reflects ACDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Australia/Adelaide
  • Australia/Broken_Hill
  • Australia/South
  • Australia/Yancowinna
Time zones with the GMT +10:30 offset:
  • ACDT - Australian Central Daylight Time
  • LHST - Lord Howe Standard Time