IST to AST Converter
AST is 9 hours 30 minutes behind IST. 9:00 AM IST = 11:30 PM AST (previous day).
AST is 9 hours 30 minutes behind IST at the moment. To convert IST to AST, subtract 9 hours 30 minutes from the IST time: 9:00 AM IST = 11:30 PM AST (previous day).
IST (India Time) is used in India and Sri Lanka (UTC+5:30, no daylight saving time). AST (Atlantic Time) is used in Nova Scotia, New Brunswick, PEI; Puerto Rico and the Eastern Caribbean (all year).
IST here means India Standard Time, not Irish or Israel Standard Time. AST here is Atlantic Standard Time, not Arabia Standard Time.
IST to AST time conversion table
IST to AST on 7 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| IST | AST | Day |
|---|---|---|
| 12:00 AM IST | 2:30 PM AST | previous day |
| 1:00 AM IST | 3:30 PM AST | previous day |
| 2:00 AM IST | 4:30 PM AST | previous day |
| 3:00 AM IST | 5:30 PM AST | previous day |
| 4:00 AM IST | 6:30 PM AST | previous day |
| 5:00 AM IST | 7:30 PM AST | previous day |
| 6:00 AM IST | 8:30 PM AST | previous day |
| 7:00 AM IST | 9:30 PM AST | previous day |
| 8:00 AM IST | 10:30 PM AST | previous day |
| 9:00 AM IST | 11:30 PM AST | previous day |
| 10:00 AM IST | 12:30 AM AST | night |
| 11:00 AM IST | 1:30 AM AST | night |
| 12:00 PM IST | 2:30 AM AST | night |
| 1:00 PM IST | 3:30 AM AST | night |
| 2:00 PM IST | 4:30 AM AST | night |
| 3:00 PM IST | 5:30 AM AST | night |
| 4:00 PM IST | 6:30 AM AST | — |
| 5:00 PM IST | 7:30 AM AST | — |
| 6:00 PM IST | 8:30 AM AST | — |
| 7:00 PM IST | 9:30 AM AST | — |
| 8:00 PM IST | 10:30 AM AST | — |
| 9:00 PM IST | 11:30 AM AST | — |
| 10:00 PM IST | 12:30 PM AST | — |
| 11:00 PM IST | 1:30 PM AST | — |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert IST to AST
Subtract 9 hours 30 minutes from the IST time to get AST.
Example: 9:00 AM IST = 11:30 PM AST (previous day).
Across midnight: 1:00 AM IST = 3:30 PM AST (previous day). The date changes, so always check the day as well as the hour.
Time difference between IST and AST
The time difference between IST 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 9 hours 30 minutes behind of IST.
- 8 Mar 2026 – 31 Oct 2026: AST is 8 hours 30 minutes behind of IST.
- 1 Nov 2026 – 31 Dec 2026: AST is 9 hours 30 minutes behind of IST.
IST and AST during daylight saving time
- IST does not observe daylight saving time; it stays on UTC+5:30 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 IST and AST
IST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM IST, which is 9:30 PM AST.
IST to AST FAQ
What is the time difference between IST and AST?
Right now AST is 9 hours 30 minutes behind IST. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM IST in AST?
9:00 AM IST is 11:30 PM AST (previous day).
What is 12 PM (noon) IST in AST?
12:00 PM IST is 2:30 AM AST.
Is AST ahead of or behind IST?
AST is 9 hours 30 minutes behind IST, so it is earlier in AST than in IST.
Does IST change for daylight saving time?
No. IST 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 IST and AST?
IST and AST have no shared 9 AM–5 PM window. The earliest slot that is reasonable on both sides is 7:00 AM IST, which is 9:30 PM AST.
Related conversions
Convert AST to IST
Convert IST to other time zones
Convert other time zones to AST
Learn more
Updated 7 November 2026. Time zone data: IANA tz database.