|

ACST to ULAST Converter

Updating current time…
ACST
Australian Central Standard Time
GMT +9:30
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ACST is not used on this date
This converter keeps ACST at GMT +9:30. Adelaide uses ACDT (GMT +10:30) on this date. Open the ACDT converter, or choose Adelaide, Adelaide Hills, or Mount Gambier for city-specific time.
ULAST
Ulaanbaatar Summer Time
GMT +9
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ULAST is not used on this date
This converter keeps ULAST at GMT +9. Ulaanbaatar uses ULAT (GMT +8) on this date. Open the ULAT converter, or choose Ulaanbaatar, Erdenet, or Darhan for city-specific time.

Quick answers

Selected conversion

The selected date and time will appear here when the converter loads.

ACST and ULAST examples

These examples always use ACST (UTC+9:30) and ULAST (UTC+9). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

ACST is 30 minutes ahead of ULAST.

How the time difference changes

ACST is 30 minutes ahead of ULAST year-round.

Working hours of 9:00 am to 5:00 pm in ACST correspond to 8:30 am to 4:30 pm in ULAST.

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

Time Difference

Australian Central Standard Time is 0 hours and 30 minutes ahead of Ulaanbaatar Summer Time
9:30 pm21:30 in ACST is 9:00 pm21:00 in ULAST

ACST to ULAST call time
Best time for a conference call or a meeting is between 9:30am-5pm in ACST which corresponds to 9am-4:30pm in ULAST

9:30 pm21:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours
9:00 pm21:00 Ulaanbaatar Summer Time (ULAST). Offset UTC +9:00 hours

9:30 pm21:30 ACST / 9:00 pm21:00 ULAST

ACSTULAST
12am (midnight)11:30 pm
1am12:30 am
2am1:30 am
3am2:30 am
4am3:30 am
5am4:30 am
6am5:30 am
7am6:30 am
8am7:30 am
9am8:30 am
10am9:30 am
11am10:30 am
12pm (noon)11:30 am
1pm12:30 pm
2pm1:30 pm
3pm2:30 pm
4pm3:30 pm
5pm4:30 pm
6pm5:30 pm
7pm6:30 pm
8pm7:30 pm
9pm8:30 pm
10pm9:30 pm
11pm10:30 pm
00:0023:30
01:0000:30
02:0001:30
03:0002:30
04:0003:30
05:0004:30
06:0005:30
07:0006:30
08:0007:30
09:0008:30
10:0009:30
11:0010:30
12:0011:30
13:0012:30
14:0013:30
15:0014:30
16:0015:30
17:0016:30
18:0017:30
19:0018:30
20:0019:30
21:0020:30
22:0021:30
23:0022:30

Australian Central Standard Time

Offset: ACST is 9 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Australia

Countries using this time zone: Australia

Principal Cities: The largest city in the ACST time zone is Darwin in Australia, with about 139,902 people. Other major cities in this time zone include Palmerston, Alice Springs.

ACST Time Zone Geo Map
ACST timezone map

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).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Australian Central Standard Time (ACST) ended on Sunday, October 5, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, October 5, 2025, 3:00 am local daylight time instead. Standard time ends annually on the first Sunday of October.

Daylight saving time clock moves back for one hour from 3am to 2amStart: Australian Central Standard Time (ACST) starts on Sunday, April 5, 2026 at 3:00 am local time and clocks are set one hour back to Sunday, April 5, 2026, 2:00 am. Standard time starts annually on the first Sunday of April.

ACST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0930 - basic
  • +09:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +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.
IANA/Olson: Reflects ACST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Australia/Adelaide
  • Australia/Broken_Hill
  • Australia/Darwin
  • Australia/North
  • Australia/South
  • Australia/Yancowinna

Ulaanbaatar Summer Time

Offset: ULAST is 9 hours ahead Greenwich Mean Time (GMT) and is used in Asia

ULAST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +09 - basic short
  • +0900 - basic
  • +09:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0900 - sign character (+) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates an offset of nine hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • India - Military abbreviation for ULAST
  • I - short form of 'India'
Time zones with the GMT +9 offset:
  • AWDT - Australian Western Daylight Time
  • CHOST - Choibalsan Summer Time
  • I - India Time Zone
  • IRKST - Irkutsk Summer Time
  • JST - Japan Standard Time
  • KST - Korea Standard Time
  • PWT - Palau Time
  • TLT - East Timor Time
  • ULAST - Ulaanbaatar Summer Time
  • WIT - Eastern Indonesian Time
  • YAKT - Yakutsk Time
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT