AST to JST Converter
JST is 13 hours ahead of AST. 9:00 AM AST = 10:00 PM JST.
JST is 13 hours ahead of AST at the moment. To convert AST to JST, add 13 hours to the AST time: 9:00 AM AST = 10:00 PM JST.
AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year). JST (Japan Time) is used in Japan.
AST here is Atlantic Standard Time, not Arabia Standard Time.
AST to JST time conversion table
AST to JST on 6 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| AST | JST | Day |
|---|---|---|
| 12:00 AM AST | 1:00 PM JST | — |
| 1:00 AM AST | 2:00 PM JST | — |
| 2:00 AM AST | 3:00 PM JST | — |
| 3:00 AM AST | 4:00 PM JST | — |
| 4:00 AM AST | 5:00 PM JST | — |
| 5:00 AM AST | 6:00 PM JST | — |
| 6:00 AM AST | 7:00 PM JST | — |
| 7:00 AM AST | 8:00 PM JST | — |
| 8:00 AM AST | 9:00 PM JST | — |
| 9:00 AM AST | 10:00 PM JST | night |
| 10:00 AM AST | 11:00 PM JST | night |
| 11:00 AM AST | 12:00 AM JST | next day |
| 12:00 PM AST | 1:00 AM JST | next day |
| 1:00 PM AST | 2:00 AM JST | next day |
| 2:00 PM AST | 3:00 AM JST | next day |
| 3:00 PM AST | 4:00 AM JST | next day |
| 4:00 PM AST | 5:00 AM JST | next day |
| 5:00 PM AST | 6:00 AM JST | next day |
| 6:00 PM AST | 7:00 AM JST | next day |
| 7:00 PM AST | 8:00 AM JST | next day |
| 8:00 PM AST | 9:00 AM JST | next day |
| 9:00 PM AST | 10:00 AM JST | next day |
| 10:00 PM AST | 11:00 AM JST | next day |
| 11:00 PM AST | 12:00 PM JST | next day |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert AST to JST
Add 13 hours to the AST time to get JST.
Example: 9:00 AM AST = 10:00 PM JST.
Across midnight: 10:00 PM AST = 11:00 AM JST (next day). The date changes, so always check the day as well as the hour.
Time difference between AST and JST
The time difference between AST and JST 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:
- 31 Dec 2025 – 7 Mar 2026: JST is 13 hours ahead of AST.
- 8 Mar 2026 – 31 Oct 2026: JST is 12 hours ahead of AST.
- 1 Nov 2026 – 30 Dec 2026: JST is 13 hours ahead of AST.
AST and JST during daylight saving time
- 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).
- JST does not observe daylight saving time; it stays on UTC+9 all year.
Best time for a meeting between AST and JST
AST and JST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM AST, which is 8:00 PM JST.
AST to JST FAQ
What is the time difference between AST and JST?
Right now JST is 13 hours ahead of AST. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM AST in JST?
9:00 AM AST is 10:00 PM JST.
What is 12 PM (noon) AST in JST?
12:00 PM AST is 1:00 AM JST (next day).
Is JST ahead of or behind AST?
JST is 13 hours ahead of AST, so it is later in JST than in AST.
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.
Does JST change for daylight saving time?
No. JST stays on the same offset all year, so conversions never shift for daylight saving time.
What is the best time for a meeting between AST and JST?
AST and JST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM AST, which is 8:00 PM JST.
Related conversions
Convert JST to AST
Convert AST to other time zones
Convert other time zones to JST
Learn more
Updated 6 November 2026. Time zone data: IANA tz database.