JST to AST Converter
AST is 13 hours behind JST. 9:00 AM JST = 8:00 PM AST (previous day).
AST is 13 hours behind JST at the moment. To convert JST to AST, subtract 13 hours from the JST time: 9:00 AM JST = 8:00 PM AST (previous day).
JST (Japan Time) is used in Japan. 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.
JST to AST time conversion table
JST to AST on 7 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| JST | AST |
|---|---|
| 12:00 AM | 11:00 AM−1 |
| 1:00 AM | 12:00 PM−1 |
| 2:00 AM | 1:00 PM−1 |
| 3:00 AM | 2:00 PM−1 |
| 4:00 AM | 3:00 PM−1 |
| 5:00 AM | 4:00 PM−1 |
| 6:00 AM | 5:00 PM−1 |
| 7:00 AM | 6:00 PM−1 |
| JST | AST |
|---|---|
| 8:00 AM | 7:00 PM−1 |
| 9:00 AM | 8:00 PM−1 |
| 10:00 AM | 9:00 PM−1 |
| 11:00 AM | 10:00 PM−1 |
| 12:00 PM | 11:00 PM−1 |
| 1:00 PM | 12:00 AM |
| 2:00 PM | 1:00 AM |
| 3:00 PM | 2:00 AM |
| JST | AST |
|---|---|
| 4:00 PM | 3:00 AM |
| 5:00 PM | 4:00 AM |
| 6:00 PM | 5:00 AM |
| 7:00 PM | 6:00 AM |
| 8:00 PM | 7:00 AM |
| 9:00 PM | 8:00 AM |
| 10:00 PM | 9:00 AM |
| 11:00 PM | 10:00 AM |
Conversion table from JST to AST for 7 Nov 2026. A tick marks hours that fall between 9 AM and 5 PM in both places. +1 means the next day in AST, −1 the previous day.
- ✓ marks 9 AM–5 PM in both places
- Greyed times are night in the destination (10 PM–6 AM)
How to convert JST to AST
Subtract 13 hours from the JST time to get AST.
Example: 9:00 AM JST = 8:00 PM AST (previous day).
Across midnight: 1:00 AM JST = 12:00 PM AST (previous day). The date changes, so always check the day as well as the hour.
Time difference between JST and AST
The time difference between JST 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 JST.
- 8 Mar 2026 – 31 Oct 2026: AST is 12 hours behind of JST.
- 1 Nov 2026 – 31 Dec 2026: AST is 13 hours behind of JST.
JST and AST during daylight saving time
- JST 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 JST and AST
JST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM JST, which is 6:00 PM AST.
JST to AST FAQ
What is the time difference between JST and AST?
Right now AST is 13 hours behind JST. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM JST in AST?
9:00 AM JST is 8:00 PM AST (previous day).
What is 12 PM (noon) JST in AST?
12:00 PM JST is 11:00 PM AST (previous day).
Is AST ahead of or behind JST?
AST is 13 hours behind JST, so it is earlier in AST than in JST.
Does JST change for daylight saving time?
No. JST 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 JST and AST?
JST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM JST, which is 6:00 PM AST.
Related conversions
Convert AST to JST
Convert JST to other time zones
Convert other time zones to AST
Learn more
Updated 7 November 2026. Time zone data: IANA tz database.