JST to AST Converter

Converting Japan Standard Time to Atlantic Standard Time

Japan Standard Time (JST) and Atlantic Standard Time (AST) are separated by a 13 hours time difference. AST is 13 hours behind JST. JST is UTC+9, used in Japan, while AST is UTC-4, used in Canada, Puerto Rico, US Virgin Islands.

When converting from JST to AST, the key reference points to remember are: 9:00 AM JST equals 8:00 PM AST, 12:00 PM noon JST equals 11:00 PM AST, and 5:00 PM JST equals 4:00 AM AST. The conversion table above shows every hour of the day mapped between these two time zones.

Scheduling Across JST and AST

For professionals scheduling meetings between JST and AST, 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

JST does not observe Daylight Saving Time, maintaining UTC+9 year-round. AST observes DST, switching to ADT (UTC-3). 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.