Updating current time…
CAST
Casey Time
GMT +8
12am
3am
6am
9am
12pm
3pm
6pm
9pm
KST
Korea Standard Time
GMT +9
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

8:00 pm20:00 CAST (UTC+8), Oct 9, 2026 = 9:00 pm21:00 KST (UTC+9), Oct 9, 2026

CAST is 1 hour behind KST.

CAST and KST examples

These examples always use CAST (UTC+8) 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.

CAST is 1 hour behind KST.

How the time difference changes

CAST is 1 hour behind KST year-round.

Working hours of 9:00 am to 5:00 pm in CAST correspond to 10:00 am to 6:00 pm in KST.Working hours of 09:00 to 17:00 in CAST correspond to 10:00 to 18:00 in KST.

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

Time Difference

Casey Time is 1 hour behind Korea Standard Time.
8:00 pm20:00 in CAST is 9:00 pm21:00 in KST

CAST to KST call time
Best time for a conference call or a meeting is between 9am-4pm09:00-16:00 in CAST which corresponds to 10am-5pm10:00-17:00 in KST

8:00 pm20:00 Casey Time (CAST). Offset UTC +8:00 hours
9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours

8:00 pm20:00 CAST / 9:00 pm21:00 KST

CASTKST
12:00am1:00am
1:00am2:00am
2:00am3:00am
3:00am4:00am
4:00am5:00am
5:00am6:00am
6:00am7:00am
7:00am8:00am
8:00am9:00am
9:00am10:00am
10:00am11:00am
11:00am12:00pm
12:00pm1:00pm
1:00pm2:00pm
2:00pm3:00pm
3:00pm4:00pm
4:00pm5:00pm
5:00pm6:00pm
6:00pm7:00pm
7:00pm8:00pm
8:00pm9:00pm
9:00pm10:00pm
10:00pm11:00pm
11:00pm12:00am
00:0001:00
01:0002:00
02:0003:00
03:0004:00
04:0005:00
05:0006:00
06:0007:00
07:0008:00
08:0009:00
09:0010:00
10:0011:00
11:0012:00
12:0013:00
13:0014:00
14:0015:00
15:0016:00
16:0017:00
17:0018:00
18:0019:00
19:0020:00
20:0021:00
21:0022:00
22:0023:00
23:0000:00

Casey Time

Offset: CAST is 8 hours ahead Greenwich Mean Time (GMT) and is used in Antarctica

Countries using this time zone: Antarctica

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

CAST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +08 - basic short
  • +0800 - basic
  • +08:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0800 - sign character (+) followed by a four digit time providing hours (08) and minutes (00) of the offset. Indicates an offset of eight hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Hotel - Military abbreviation for CAST
  • H - short form of 'Hotel'
Time zones with the GMT +8 offset:
  • ACT - ASEAN Common Time
  • AWST - Australian Western Standard Time
  • BNT - Brunei Darussalam Time
  • CAST - Casey Time
  • CHOT - Choibalsan Time
  • CST - China Standard Time
  • H - Hotel Time Zone
  • HKT - Hong Kong Time
  • HOVST - Hovd Summer Time
  • IRKT - Irkutsk Time
  • KRAST - Krasnoyarsk Summer Time
  • MYT - Malaysia Time
  • PHT - Philippine Time
  • SGT - Singapore Time
  • ULAT - Ulaanbaatar Time
  • WITA - Central Indonesian Time

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; see upcoming clock changes worldwide.

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