MST to ACST Converter
South Australia is on daylight saving time: ACDT (UTC+10:30) until Sun, Apr 4, 2027.
The Northern Territory stays on ACST (UTC+9:30).
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.
Quick answers
Selected conversion
9:00 am09:00 MST (UTC-7), Nov 1, 2026 = 1:30 am01:30 ACST (UTC+9:30), Nov 2, 2026
MST is 16 hours and 30 minutes behind ACST.
MST and ACST examples
These examples always use MST (UTC-7) and ACST (UTC+9:30). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
MST is 16 hours and 30 minutes behind ACST.
Most of Arizona stays on MST (UTC-7) all year. Places such as Denver use MDT (UTC-6) during daylight saving time, one hour later. For daylight-time examples, use MDT to ACST.
How the time difference changes
For most of the year, MDT is 15 hours and 30 minutes behind ACST. From Nov 1, 2026 to Mar 14, 2027, MST is 16 hours and 30 minutes behind ACST.
For most of the year, 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. At other times of the year, working hours of 9:00 am to 6:00 pm in MST correspond to 1:30 am (next day) to 10:30 am (next day) in ACST.For most of the year, working hours of 09:00 to 18:00 in MDT correspond to 00:30 (next day) to 09:30 (next day) in ACST. At other times of the year, working hours of 09:00 to 18:00 in MST correspond to 01:30 (next day) to 10:30 (next day) in ACST.
Compare MST time with ACST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Mountain Standard Time is 16 hours and 30 minutes behind Australian Central Standard Time.
9:00 am09:00 in MST is 1:30 am01:30 in ACST
MST to ACST call time
Best time for a conference call or a meeting is between 4:30pm-6pm16:30-18:00 in MST which corresponds to 9am-10:30am09:00-10:30 in ACST (next day)
9:00 am09:00 Mountain Standard Time (MST). Offset UTC -7:00 hours
1:30 am01:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours
9:00 am09:00 MST / 1:30 am01:30 ACST
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.
| MST | ACST |
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Mountain Standard Time
Offset: MST is 7 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Canada, Mexico, United States
Principal Cities: The largest city in the MST time zone is Phoenix in the United States, with about 1.65 million people. Other major cities in this time zone include Ciudad Juárez, Hermosillo, Culiacán, Denver.
French: HNR - Heure Normale des Rocheuses
Spanish: MT - Zona Pacífico
Today all shaded areas are on MST.
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Mountain Daylight Time (MDT).
Start: Mountain Standard Time (MST) started 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. Standard time starts annually on the first Sunday of November.
End: Mountain Standard Time (MST) ends 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 local daylight time instead. Standard time ends annually on the second Sunday of March.
See USA daylight saving time and upcoming clock changes worldwide.
MST representations, usage and related time zones
- -07 - basic short
- -0700 - basic
- -07:00 - extended
- -0700 - sign character (-) followed by a four digit time providing hours (07) and minutes (00) of the offset. Indicates an offset of seven hours to the west of the zero meridian.
- Tango - Military abbreviation for MST
- T - short form of 'Tango'
- America/Boise
- America/Cambridge_Bay
- America/Ciudad_Juarez
- America/Creston
- America/Dawson
- America/Dawson_Creek
- America/Denver
- America/Edmonton
- America/Fort_Nelson
- America/Hermosillo
- America/Inuvik
- America/Mazatlan
- America/Phoenix
- America/Shiprock
- America/Whitehorse
- America/Yellowknife
- Canada/Mountain
- Canada/Yukon
- MST
- MST7MDT
- Mexico/BajaSur
- Navajo
- US/Arizona
- US/Mountain
- MST - Mountain Standard Time
- PDT - Pacific Daylight Time
- YST - Yukon Standard Time
- T - Tango Time Zone
Australian Central Standard Time
Offset: ACST is 9 hours and 30 minutes ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Australia
Principal Cities: The largest city in the ACST time zone is Adelaide in Australia, with about 1.469 million people. Other major cities in this time zone include Darwin, Palmerston, Alice Springs, Mount Gambier.
Today the lighter areas are on UTC+10:30 (ACDT).
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Australian Central Daylight Time (ACDT).
End: Australian Central Standard Time (ACST) ended 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 local daylight time instead. Standard time ends annually on the first Sunday of October.
Start: Australian Central Standard Time (ACST) starts 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. Standard time starts annually on the first Sunday of April.
See Australia daylight saving time and upcoming clock changes worldwide.
ACST representations, usage and related time zones
- +0930 - basic
- +09:30 - extended
- +0930 - sign character (+) followed by a four digit time providing hours (09) and minutes (30) of the offset. Indicates an offset of nine hours and thirty minutes to the east of the zero meridian.
- Australia/Adelaide
- Australia/Broken_Hill
- Australia/Darwin
- Australia/North
- Australia/South
- Australia/Yancowinna