KST to AST Converter
AST is 13 hours behind KST. 9:00 AM KST = 8:00 PM AST (previous day).
AST is 13 hours behind KST at the moment. To convert KST to AST, subtract 13 hours from the KST time: 9:00 AM KST = 8:00 PM AST (previous day).
KST (Korea Time) is used in South Korea. AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year).
AST here is Atlantic Standard Time, not Arabia Standard Time.
KST to AST time conversion table
KST to AST on 7 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| KST | AST | Day |
|---|---|---|
| 12:00 AM KST | 11:00 AM AST | previous day |
| 1:00 AM KST | 12:00 PM AST | previous day |
| 2:00 AM KST | 1:00 PM AST | previous day |
| 3:00 AM KST | 2:00 PM AST | previous day |
| 4:00 AM KST | 3:00 PM AST | previous day |
| 5:00 AM KST | 4:00 PM AST | previous day |
| 6:00 AM KST | 5:00 PM AST | previous day |
| 7:00 AM KST | 6:00 PM AST | previous day |
| 8:00 AM KST | 7:00 PM AST | previous day |
| 9:00 AM KST | 8:00 PM AST | previous day |
| 10:00 AM KST | 9:00 PM AST | previous day |
| 11:00 AM KST | 10:00 PM AST | previous day |
| 12:00 PM KST | 11:00 PM AST | previous day |
| 1:00 PM KST | 12:00 AM AST | night |
| 2:00 PM KST | 1:00 AM AST | night |
| 3:00 PM KST | 2:00 AM AST | night |
| 4:00 PM KST | 3:00 AM AST | night |
| 5:00 PM KST | 4:00 AM AST | night |
| 6:00 PM KST | 5:00 AM AST | night |
| 7:00 PM KST | 6:00 AM AST | — |
| 8:00 PM KST | 7:00 AM AST | — |
| 9:00 PM KST | 8:00 AM AST | — |
| 10:00 PM KST | 9:00 AM AST | — |
| 11:00 PM KST | 10:00 AM AST | — |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert KST to AST
Subtract 13 hours from the KST time to get AST.
Example: 9:00 AM KST = 8:00 PM AST (previous day).
Across midnight: 1:00 AM KST = 12:00 PM AST (previous day). The date changes, so always check the day as well as the hour.
Time difference between KST and AST
The time difference between KST and AST is not the same all year, because the two sides change for daylight saving time on different dates. In 2026 it works out like this:
- 1 Jan 2026 – 7 Mar 2026: AST is 13 hours behind of KST.
- 8 Mar 2026 – 31 Oct 2026: AST is 12 hours behind of KST.
- 1 Nov 2026 – 31 Dec 2026: AST is 13 hours behind of KST.
KST and AST during daylight saving time
- KST does not observe daylight saving time; it stays on UTC+9 all year.
- AST next changes on 14 Mar 2027: clocks go forward one hour at 01:59 local time, from AST (UTC−4) to ADT (UTC−3).
Best time for a meeting between KST and AST
KST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM KST, which is 6:00 PM AST.
KST to AST FAQ
What is the time difference between KST and AST?
Right now AST is 13 hours behind KST. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM KST in AST?
9:00 AM KST is 8:00 PM AST (previous day).
What is 12 PM (noon) KST in AST?
12:00 PM KST is 11:00 PM AST (previous day).
Is AST ahead of or behind KST?
AST is 13 hours behind KST, so it is earlier in AST than in KST.
Does KST change for daylight saving time?
No. KST stays on the same offset all year, so conversions never shift for daylight saving time.
Does AST change for daylight saving time?
Yes. AST next changes on 14 Mar 2027, when clocks go forward one hour from AST to ADT.
What is the best time for a meeting between KST and AST?
KST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM KST, which is 6:00 PM AST.
Related conversions
Convert AST to KST
Convert KST to other time zones
Convert other time zones to AST
Learn more
Updated 7 November 2026. Time zone data: IANA tz database.