Updating current time…
KST
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ACST
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ACST is not used on this date
This converter keeps ACST at UTC+9:30. Adelaide uses ACDT (UTC+10:30) on this date. Open the ACDT converter, or choose Adelaide, Adelaide Hills, or Mount Gambier for city-specific time.

Quick answers

Selected conversion

9:00 pm21:00 KST (UTC+9), Oct 18, 2026 = 9:30 pm21:30 ACST (UTC+9:30), Oct 18, 2026

KST is 30 minutes behind ACST.

KST and ACST examples

These examples always use KST (UTC+9) 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.

KST is 30 minutes behind ACST.

How the time difference changes

KST is 30 minutes behind ACST year-round.

Working hours of 9:00 am to 6:00 pm in KST correspond to 9:30 am to 6:30 pm in ACST.Working hours of 09:00 to 18:00 in KST correspond to 09:30 to 18:30 in ACST.

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

Time Difference

Korea Standard Time is 30 minutes behind Australian Central Standard Time.
9:00 pm21:00 in KST is 9:30 pm21:30 in ACST

KST to ACST call time
Best time for a conference call or a meeting is between 9am-5:30pm09:00-17:30 in KST which corresponds to 9:30am-6pm09:30-18:00 in ACST

9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours
9:30 pm21:30 Australian Central Standard Time (ACST). Offset UTC +9:30 hours

9:00 pm21:00 KST / 9:30 pm21:30 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.

Hourly time comparison
KSTACST
12:30am
1:30am
2:30am
3:30am
4:30am
5:30am
6:30am
7:30am
8:30am
9:30am
10:30am
11:30am
12:30pm
1:30pm
2:30pm
3:30pm
4:30pm
5:30pm
6:30pm
7:30pm
8:30pm
9:30pm
10:30pm
11:30pm
00:30
01:30
02:30
03:30
04:30
05:30
06:30
07:30
08:30
09:30
10:30
11:30
12:30
13:30
14:30
15:30
16:30
17:30
18:30
19:30
20:30
21:30
22:30
23:30

Korea Standard Time

Offset: KST is 9 hours ahead of Greenwich Mean Time (GMT).

Countries using this time zone: North Korea, South Korea

Principal Cities: The largest city in the KST time zone is Seoul in South Korea, with about 10.349 million people. Other major cities in this time zone include Busan, Pyongyang, Incheon, Daegu.

Daylight Saving: Clocks in Korea Standard Time (KST) do not change for daylight saving time, so KST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.

KST 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 KST
  • I - short form of 'India'
IANA/Olson: Reflects KST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Pyongyang
  • Asia/Seoul
  • ROK
KST Abbreviation: Several time zones share KST abbreviation and it could refer to these time zones
  • Korea Standard Time - UTC +9
  • Pyongyang Time - UTC +8:30
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 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.

Map of the areas on Australian Central Standard Time (ACST)
ACST all year ACST part of the year

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).

123456789101112End: 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.

123456789101112Start: 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

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