KST to CAST Converter
Quick answers
Selected conversion
9:00 pm21:00 KST (UTC+9), Oct 9, 2026 = 8:00 pm20:00 CAST (UTC+8), Oct 9, 2026
KST is 1 hour ahead of CAST.
KST and CAST examples
These examples always use KST (UTC+9) and CAST (UTC+8). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
KST is 1 hour ahead of CAST.
How the time difference changes
KST is 1 hour ahead of CAST year-round.
Working hours of 9:00 am to 5:00 pm in KST correspond to 8:00 am to 4:00 pm in CAST.Working hours of 09:00 to 17:00 in KST correspond to 08:00 to 16:00 in CAST.
Compare KST time with CAST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Korea Standard Time is 1 hour ahead of Casey Time.
9:00 pm21:00 in KST is 8:00 pm20:00 in CAST
KST to CAST call time
Best time for a conference call or a meeting is between 10am-5pm10:00-17:00 in KST which corresponds to 9am-4pm09:00-16:00 in CAST
9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours
8:00 pm20:00 Casey Time (CAST). Offset UTC +8:00 hours
9:00 pm21:00 KST / 8:00 pm20:00 CAST
| KST | CAST |
|---|---|
| 12:00am | 11:00pm |
| 1:00am | 12:00am |
| 2:00am | 1:00am |
| 3:00am | 2:00am |
| 4:00am | 3:00am |
| 5:00am | 4:00am |
| 6:00am | 5:00am |
| 7:00am | 6:00am |
| 8:00am | 7:00am |
| 9:00am | 8:00am |
| 10:00am | 9:00am |
| 11:00am | 10:00am |
| 12:00pm | 11:00am |
| 1:00pm | 12:00pm |
| 2:00pm | 1:00pm |
| 3:00pm | 2:00pm |
| 4:00pm | 3:00pm |
| 5:00pm | 4:00pm |
| 6:00pm | 5:00pm |
| 7:00pm | 6:00pm |
| 8:00pm | 7:00pm |
| 9:00pm | 8:00pm |
| 10:00pm | 9:00pm |
| 11:00pm | 10:00pm |
| 00:00 | 23:00 |
| 01:00 | 00:00 |
| 02:00 | 01:00 |
| 03:00 | 02:00 |
| 04:00 | 03:00 |
| 05:00 | 04:00 |
| 06:00 | 05:00 |
| 07:00 | 06:00 |
| 08:00 | 07:00 |
| 09:00 | 08:00 |
| 10:00 | 09:00 |
| 11:00 | 10:00 |
| 12:00 | 11:00 |
| 13:00 | 12:00 |
| 14:00 | 13:00 |
| 15:00 | 14:00 |
| 16:00 | 15:00 |
| 17:00 | 16:00 |
| 18:00 | 17:00 |
| 19:00 | 18:00 |
| 20:00 | 19:00 |
| 21:00 | 20:00 |
| 22:00 | 21:00 |
| 23:00 | 22:00 |
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 representations, usage and related time zones
- +09 - basic short
- +0900 - basic
- +09:00 - extended
- +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.
- India - Military abbreviation for KST
- I - short form of 'India'
- Asia/Pyongyang
- Asia/Seoul
- ROK
- Korea Standard Time - UTC +9
- Pyongyang Time - UTC +8:30
- 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
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
- +08 - basic short
- +0800 - basic
- +08:00 - extended
- +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.
- Hotel - Military abbreviation for CAST
- H - short form of 'Hotel'
- 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