JST to AST converter
AST is 13 hours behind of JST today. JST (Japan Standard Time) - currently UTC+9; AST (Atlantic Standard Time) - currently UTC−4.
The 09:00-18:00 workdays in JST and AST don't overlap at all, so one side always works early or late. Quick answers: 9 AM JST = 8 PM AST (previous day), 12 PM JST = 11 PM AST (previous day), 5 PM JST = 4 AM AST.
Convert a time
AST
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Working hours side by side
columns: JST hours PING · 09–18 local MAYBE · 07–09, 18–21 NOT NOW · 21–07Outlined: everyone can be pinged
JST to AST conversion table
| JST | AST | Verdict in AST |
|---|---|---|
| 12 AM · 00:00 | 11 AM · 11:00 (previous day) | PING |
| 1 AM · 01:00 | 12 PM · 12:00 (previous day) | PING |
| 2 AM · 02:00 | 1 PM · 13:00 (previous day) | PING |
| 3 AM · 03:00 | 2 PM · 14:00 (previous day) | PING |
| 4 AM · 04:00 | 3 PM · 15:00 (previous day) | PING |
| 5 AM · 05:00 | 4 PM · 16:00 (previous day) | PING |
| 6 AM · 06:00 | 5 PM · 17:00 (previous day) | PING |
| 7 AM · 07:00 | 6 PM · 18:00 (previous day) | MAYBE |
| 8 AM · 08:00 | 7 PM · 19:00 (previous day) | MAYBE |
| 9 AM · 09:00 | 8 PM · 20:00 (previous day) | MAYBE |
| 10 AM · 10:00 | 9 PM · 21:00 (previous day) | NOT NOW |
| 11 AM · 11:00 | 10 PM · 22:00 (previous day) | NOT NOW |
| 12 PM · 12:00 | 11 PM · 23:00 (previous day) | NOT NOW |
| 1 PM · 13:00 | 12 AM · 00:00 | NOT NOW |
| 2 PM · 14:00 | 1 AM · 01:00 | NOT NOW |
| 3 PM · 15:00 | 2 AM · 02:00 | NOT NOW |
| 4 PM · 16:00 | 3 AM · 03:00 | NOT NOW |
| 5 PM · 17:00 | 4 AM · 04:00 | NOT NOW |
| 6 PM · 18:00 | 5 AM · 05:00 | NOT NOW |
| 7 PM · 19:00 | 6 AM · 06:00 | NOT NOW |
| 8 PM · 20:00 | 7 AM · 07:00 | MAYBE |
| 9 PM · 21:00 | 8 AM · 08:00 | MAYBE |
| 10 PM · 22:00 | 9 AM · 09:00 | PING |
| 11 PM · 23:00 | 10 AM · 10:00 | PING |
Cities on JST
Asia/TokyoCities on AST
America/HalifaxOther conversions
All convertersQuestions
What is the time difference between JST and AST?
AST (Atlantic Standard Time) is 13 hours behind of JST (Japan Standard Time) right now: UTC+9 versus UTC−4.
What is 9 AM JST in AST?
9:00 AM JST is 8 PM AST (previous day).
What is 5 PM JST in AST?
5:00 PM JST is 4 AM AST.
Does daylight saving change the JST–AST difference?
JST has no daylight saving; it stays UTC+9 all year. Halifax switches between AST; next change Sunday, 14 March 2027 (UTC−4 → UTC−3).