Updating current time…
IST
12am
3am
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12pm
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6pm
9pm
KST
12am
3am
6am
9am
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9pm

Quick answers

Selected conversion

5:30 pm17:30 IST (UTC+5:30), Oct 12, 2026 = 9:00 pm21:00 KST (UTC+9), Oct 12, 2026

IST is 3 hours and 30 minutes behind KST.

IST and KST examples

These examples always use IST (UTC+5:30) and KST (UTC+9). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

IST is 3 hours and 30 minutes behind KST.

How the time difference changes

IST is 3 hours and 30 minutes behind KST year-round.

Working hours of 9:00 am to 5:00 pm in IST correspond to 12:30 pm to 8:30 pm in KST.Working hours of 09:00 to 17:00 in IST correspond to 12:30 to 20:30 in KST.

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

Time Difference

India Standard Time is 3 hours and 30 minutes behind Korea Standard Time.
5:30 pm17:30 in IST is 9:00 pm21:00 in KST

IST to KST call time
Best time for a conference call or a meeting is between 9am-1:30pm09:00-13:30 in IST which corresponds to 12:30pm-5pm12:30-17:00 in KST

5:30 pm17:30 India Standard Time (IST). Offset UTC +5:30 hours
9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours

5:30 pm17:30 IST / 9:00 pm21:00 KST

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Hourly time comparison
ISTKST
3:30am
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12:30am next day
1:30am next day
2:30am next day
03:30
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India Standard Time

Offset: IST is 5 hours and 30 minutes ahead of Greenwich Mean Time (GMT).

Countries using this time zone: India

Principal Cities: The largest city in the IST time zone is Mumbai in India, with about 12.692 million people. Other major cities in this time zone include Delhi, Bengaluru, Hyderabad, Ahmedabad.

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

IST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0530 - basic
  • +05:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0530 - sign character (+) followed by a four digit time providing hours (05) and minutes (30) of the offset. Indicates an offset of five hours and thirty minutes to the east of the zero meridian.
IANA/Olson: Reflects IST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Calcutta
  • Asia/Kolkata
IST Abbreviation: Several time zones share IST abbreviation and it could refer to these time zones
  • India Standard Time - UTC +5:30
  • Irish Standard Time - UTC +1
  • Israel Standard Time - UTC +2

Korea Standard Time

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

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; 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