AST to JST Converter
JST is 13 hours ahead of AST
AST to JST Conversion Table
Green rows indicate standard business hours (9 AM – 5 PM) in JST
| AST | JST |
|---|---|
| 12:00 AM | 1:00 PM |
| 1:00 AM | 2:00 PM |
| 2:00 AM | 3:00 PM |
| 3:00 AM | 4:00 PM |
| 4:00 AM | 5:00 PM |
| 5:00 AM | 6:00 PM |
| 6:00 AM | 7:00 PM |
| 7:00 AM | 8:00 PM |
| 8:00 AM | 9:00 PM |
| 9:00 AM | 10:00 PM |
| 10:00 AM | 11:00 PM |
| 11:00 AM | 12:00 AM +1d |
| 12:00 PM | 1:00 AM +1d |
| 1:00 PM | 2:00 AM +1d |
| 2:00 PM | 3:00 AM +1d |
| 3:00 PM | 4:00 AM +1d |
| 4:00 PM | 5:00 AM +1d |
| 5:00 PM | 6:00 AM +1d |
| 6:00 PM | 7:00 AM +1d |
| 7:00 PM | 8:00 AM +1d |
| 8:00 PM | 9:00 AM +1d |
| 9:00 PM | 10:00 AM +1d |
| 10:00 PM | 11:00 AM +1d |
| 11:00 PM | 12:00 PM +1d |
Converting Atlantic Standard Time to Japan Standard Time
Atlantic Standard Time (AST) and Japan Standard Time (JST) are separated by a 13 hours time difference. JST is 13 hours ahead of AST. AST is UTC-4, used in Canada, Puerto Rico, US Virgin Islands, while JST is UTC+9, used in Japan.
When converting from AST to JST, the key reference points to remember are: 9:00 AM AST equals 10:00 PM JST, 12:00 PM noon AST equals 1:00 AM JST, and 5:00 PM AST equals 6:00 AM JST. The conversion table above shows every hour of the day mapped between these two time zones.
Scheduling Across AST and JST
For professionals scheduling meetings between AST and JST, finding overlapping business hours is essential. Standard business hours are typically 9:00 AM to 5:00 PM in each time zone. Given the 13 hours difference, the window of overlap may be limited, making early morning or late evening calls necessary for one party. Use the highlighted working hours in the conversion table above to quickly identify suitable meeting times.
Daylight Saving Time Considerations
AST observes Daylight Saving Time, switching to ADT (UTC-3) during summer months. JST does not observe DST, staying at UTC+9 year-round. During DST transitions, the time difference between these zones may temporarily change by 1 hour. Always verify the current offset during spring and fall transition periods.