KST
Korea Standard Time
GMT +9
12am
3am
6am
9am
12pm
3pm
6pm
9pm
IRST
Iran Standard Time
GMT +3:30
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

KST is 5 hours and 30 minutes ahead of IRST. KST uses GMT +9, and IRST uses GMT +3:30 for this comparison.

For example, 9:00 pm KST is 3:30 pm IRST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 2:30pm-5pm KST, which is 9am-11:30am IRST.

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

Time Difference

Korea Standard Time is 5 hours and 30 minutes ahead of Iran Standard Time
9:00 pm21:00 in KST is 3:30 pm15:30 in IRST

KST to IRST call time
Best time for a conference call or a meeting is between 2:30pm-5pm in KST which corresponds to 9am-11:30am in IRST

9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours
3:30 pm15:30 Iran Standard Time (IRST). Offset UTC +3:30 hours

9:00 pm21:00 KST / 3:30 pm15:30 IRST

KSTIRST
12am (midnight)6:30 pm
1am7:30 pm
2am8:30 pm
3am9:30 pm
4am10:30 pm
5am11:30 pm
6am12:30 am
7am1:30 am
8am2:30 am
9am3:30 am
10am4:30 am
11am5:30 am
12pm (noon)6:30 am
1pm7:30 am
2pm8:30 am
3pm9:30 am
4pm10:30 am
5pm11:30 am
6pm12:30 pm
7pm1:30 pm
8pm2:30 pm
9pm3:30 pm
10pm4:30 pm
11pm5:30 pm
00:0018:30
01:0019:30
02:0020:30
03:0021:30
04:0022:30
05:0023:30
06:0000:30
07:0001:30
08:0002:30
09:0003:30
10:0004:30
11:0005:30
12:0006:30
13:0007:30
14:0008:30
15:0009:30
16:0010:30
17:0011:30
18:0012:30
19:0013:30
20:0014:30
21:0015:30
22:0016:30
23:0017:30

Korea Standard Time

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

Countries using this time zone: Korea (North), Korea (South)

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.

KST Time Zone Geo Map
KST timezone map

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

Iran Standard Time

Offset: IRST is 3 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: Iran

Principal Cities: The largest city in the IRST time zone is Tehran in Iran, with about 7.153 million people. Other major cities in this time zone include Mashhad, Isfahan, Karaj, Tabriz.

Daylight Saving: Clocks in Iran Standard Time (IRST) do not change for daylight saving time, so IRST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

IRST Time Zone Geo Map
IRST timezone map

IRST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0330 - basic
  • +03:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0330 - sign character (+) followed by a four digit time providing hours (03) and minutes (30) of the offset. Indicates an offset of three hours and thirty minutes to the east of the zero meridian.