IRKT/IRKST
Irkutsk Time
GMT +8
12am
3am
6am
9am
12pm
3pm
6pm
9pm
IRKST is not used on this date
This converter uses IRKT (GMT +8), the offset Irkutsk uses on this date. Open the IRKT converter.
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.

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

Time Difference

Irkutsk Time is 1 hour and 30 minutes behind Australian Central Standard Time
8:00 pm20:00 in IRKT is 9:30 pm21:30 in ACST

IRKT to ACST call time
Best time for a conference call or a meeting is between 9am-3:30pm in IRKT which corresponds to 10:30am-5pm in ACST

8:00 pm20:00 Irkutsk Time (IRKT). Offset UTC +8:00 hours
9:30 pm21:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours

8:00 pm20:00 IRKT / 9:30 pm21:30 ACST

IRKTACST
12am (midnight)1:30 am
1am2:30 am
2am3:30 am
3am4:30 am
4am5:30 am
5am6:30 am
6am7:30 am
7am8:30 am
8am9:30 am
9am10:30 am
10am11:30 am
11am12:30 pm
12pm (noon)1:30 pm
1pm2:30 pm
2pm3:30 pm
3pm4:30 pm
4pm5:30 pm
5pm6:30 pm
6pm7:30 pm
7pm8:30 pm
8pm9:30 pm
9pm10:30 pm
10pm11:30 pm
11pm12:30 am
00:0001:30
01:0002:30
02:0003:30
03:0004:30
04:0005:30
05:0006:30
06:0007:30
07:0008:30
08:0009:30
09:0010:30
10:0011:30
11:0012:30
12:0013:30
13:0014:30
14:0015:30
15:0016:30
16:0017:30
17:0018:30
18:0019:30
19:0020:30
20:0021:30
21:0022:30
22:0023:30
23:0000:30

Irkutsk Summer Time

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

IRKST 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 IRKST
  • 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

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 129,062 people. Other major cities in this time zone include Alice Springs, Palmerston.

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