AST to KST Converter
Quick answers
AST is 13 hours behind KST. AST uses GMT -4, and KST uses GMT +9 for this comparison.
For example, 8:00 am AST is 9:00 pm KST. Use the converter above to adjust the date or time and create a shareable meeting link.
Best meeting overlap: 6pm-7pm AST, which is 7am-8am KST (next day).
Compare AST time with KST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Atlantic Standard Time is 13 hours behind Korea Standard Time
8:00 am08:00 in AST is 9:00 pm21:00 in KST
AST to KST call time
Best time for a conference call or a meeting is between 6pm-7pm in AST which corresponds to 7am-8am in KST (next day)
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours
8:00 am08:00 AST / 9:00 pm21:00 KST
| AST | KST |
|---|---|
| 12am (midnight) | 1pm |
| 1am | 2pm |
| 2am | 3pm |
| 3am | 4pm |
| 4am | 5pm |
| 5am | 6pm |
| 6am | 7pm |
| 7am | 8pm |
| 8am | 9pm |
| 9am | 10pm |
| 10am | 11pm |
| 11am | 12am (midnight) |
| 12pm (noon) | 1am |
| 1pm | 2am |
| 2pm | 3am |
| 3pm | 4am |
| 4pm | 5am |
| 5pm | 6am |
| 6pm | 7am |
| 7pm | 8am |
| 8pm | 9am |
| 9pm | 10am |
| 10pm | 11am |
| 11pm | 12pm (noon) |
| 00:00 | 13:00 |
| 01:00 | 14:00 |
| 02:00 | 15:00 |
| 03:00 | 16:00 |
| 04:00 | 17:00 |
| 05:00 | 18:00 |
| 06:00 | 19:00 |
| 07:00 | 20:00 |
| 08:00 | 21:00 |
| 09:00 | 22:00 |
| 10:00 | 23:00 |
| 11:00 | 00:00 |
| 12:00 | 01:00 |
| 13:00 | 02:00 |
| 14:00 | 03:00 |
| 15:00 | 04:00 |
| 16:00 | 05:00 |
| 17:00 | 06:00 |
| 18:00 | 07:00 |
| 19:00 | 08:00 |
| 20:00 | 09:00 |
| 21:00 | 10:00 |
| 22:00 | 11:00 |
| 23:00 | 12:00 |
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries using this time zone: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)
Principal Cities: The largest city in the AST time zone is Santo Domingo in Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax.
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).
Start: Atlantic Standard Time (AST) started on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the first Sunday of November.
End: Atlantic Standard Time (AST) ends on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.
AST representations, usage and related time zones
- -04 - basic short
- -0400 - basic
- -04:00 - extended
- -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the west of the zero meridian.
- Quebec - Military abbreviation for AST
- Q - short form of 'Quebec'
- America/Anguilla
- America/Antigua
- America/Aruba
- America/Barbados
- America/Blanc-Sablon
- America/Curacao
- America/Dominica
- America/Glace_Bay
- America/Goose_Bay
- America/Grenada
- America/Guadeloupe
- America/Halifax
- America/Kralendijk
- America/Lower_Princes
- America/Marigot
- America/Martinique
- America/Moncton
- America/Montserrat
- America/Port_of_Spain
- America/Puerto_Rico
- America/Santo_Domingo
- America/St_Barthelemy
- America/St_Kitts
- America/St_Lucia
- America/St_Thomas
- America/St_Vincent
- America/Thule
- America/Tortola
- America/Virgin
- Atlantic/Bermuda
- Canada/Atlantic
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- AST - Atlantic Standard Time
- EDT - Eastern Daylight Time
- AMT - Amazon Time
- BOT - Bolivia Time
- CDT - Cuba Daylight Time
- CLT - Chile Standard Time
- FKT - Falkland Island Time
- GYT - Guyana Time
- HLV - Hora Legal de Venezuela
- PYT - Paraguay Time
- Q - Quebec Time Zone
- VET - Venezuelan Standard 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.
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