IST to AST Converter
AST is 9 hours and 30 minutes behind IST
IST to AST Conversion Table
Green rows indicate standard business hours (9 AM – 5 PM) in AST
| IST | AST |
|---|---|
| 12:00 AM | 2:30 PM -1d |
| 1:00 AM | 3:30 PM -1d |
| 2:00 AM | 4:30 PM -1d |
| 3:00 AM | 5:30 PM -1d |
| 4:00 AM | 6:30 PM -1d |
| 5:00 AM | 7:30 PM -1d |
| 6:00 AM | 8:30 PM -1d |
| 7:00 AM | 9:30 PM -1d |
| 8:00 AM | 10:30 PM -1d |
| 9:00 AM | 11:30 PM -1d |
| 10:00 AM | 12:30 AM |
| 11:00 AM | 1:30 AM |
| 12:00 PM | 2:30 AM |
| 1:00 PM | 3:30 AM |
| 2:00 PM | 4:30 AM |
| 3:00 PM | 5:30 AM |
| 4:00 PM | 6:30 AM |
| 5:00 PM | 7:30 AM |
| 6:00 PM | 8:30 AM |
| 7:00 PM | 9:30 AM |
| 8:00 PM | 10:30 AM |
| 9:00 PM | 11:30 AM |
| 10:00 PM | 12:30 PM |
| 11:00 PM | 1:30 PM |
Converting India Standard Time to Atlantic Standard Time
India Standard Time (IST) and Atlantic Standard Time (AST) are separated by a 9 hours and 30 minutes time difference. AST is 9 hours and 30 minutes behind IST. IST is UTC+5:30, used in India, Sri Lanka, while AST is UTC-4, used in Canada, Puerto Rico, US Virgin Islands.
When converting from IST to AST, the key reference points to remember are: 9:00 AM IST equals 11:30 PM AST, 12:00 PM noon IST equals 2:30 AM AST, and 5:00 PM IST equals 7:30 AM AST. The conversion table above shows every hour of the day mapped between these two time zones.
Scheduling Across IST and AST
For professionals scheduling meetings between IST 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 9 hours and 30 minutes 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
IST does not observe Daylight Saving Time, maintaining UTC+5:30 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.