AST to IST
On Oct 23, 2026, India Standard Time is 8 hours 30 minutes ahead of Atlantic Time: 9:00 AM ADT is 5:30 PM IST. The gap changes during the year because of daylight saving time; the dates are below.
IST vs AST over the next 12 months
| Period | IST is | Example |
|---|---|---|
| Oct 23, 2026 to Nov 1, 2026 | 8 hours 30 minutes ahead | 9:00 AM ADT = 5:30 PM IST |
| Nov 1, 2026 to Mar 14, 2027 | 9 hours 30 minutes ahead | 9:00 AM AST = 6:30 PM IST |
| Mar 14, 2027 onwards | 8 hours 30 minutes ahead | 9:00 AM ADT = 5:30 PM IST |
AST to IST conversion table
Every hour of a weekday around Oct 23, 2026, in both zones.
| Atlantic Time | India Standard Time |
|---|---|
| 12:00 AM | 8:30 AM |
| 1:00 AM | 9:30 AM |
| 2:00 AM | 10:30 AM |
| 3:00 AM | 11:30 AM |
| 4:00 AM | 12:30 PM |
| 5:00 AM | 1:30 PM |
| 6:00 AM | 2:30 PM |
| 7:00 AM | 3:30 PM |
| 8:00 AM | 4:30 PM |
| 9:00 AM | 5:30 PM |
| 10:00 AM | 6:30 PM |
| 11:00 AM | 7:30 PM |
| 12:00 PM | 8:30 PM |
| 1:00 PM | 9:30 PM |
| 2:00 PM | 10:30 PM |
| 3:00 PM | 11:30 PM |
| 4:00 PM | 12:30 AM (next day) |
| 5:00 PM | 1:30 AM (next day) |
| 6:00 PM | 2:30 AM (next day) |
| 7:00 PM | 3:30 AM (next day) |
| 8:00 PM | 4:30 AM (next day) |
| 9:00 PM | 5:30 AM (next day) |
| 10:00 PM | 6:30 AM (next day) |
| 11:00 PM | 7:30 AM (next day) |
Best time for a meeting
There is no 9-to-5 overlap; within an 8 AM–8 PM day the zones overlap for 3 hours 30 minutes on a weekday: 8:00 AM–11:30 AM ADT, which is 4:30 PM–8:00 PM IST.
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Daylight saving time
Atlantic Time (AST/ADT)
- Nov 1, 2026: clocks go back 1 hour at 2:00 AM (UTC−3 → UTC−4)
- Mar 14, 2027: clocks go forward 1 hour at 2:00 AM (UTC−4 → UTC−3)
Where these clocks are used
- Atlantic Time (AST/ADT): Nova Scotia, New Brunswick, Prince Edward Island. IANA zone
America/Halifax. - India Standard Time (IST): all of India: Mumbai, Delhi, Bengaluru, Chennai. IANA zone
Asia/Kolkata.
Questions
What time is it in IST when it is 9 AM AST?
On Oct 23, 2026, 9:00 AM ADT is 5:30 PM IST. On other dates the answer can shift by an hour because of daylight saving time; the table of periods on this page gives each one.
How many hours ahead of AST is IST?
It depends on the date. Oct 23, 2026 to Nov 1, 2026: IST is 8 hours 30 minutes ahead. Nov 1, 2026 to Mar 14, 2027: IST is 9 hours 30 minutes ahead. Mar 14, 2027 onwards: IST is 8 hours 30 minutes ahead.
Do AST and IST observe daylight saving time?
Atlantic Time switches to ADT (UTC−3) in summer and back to AST (UTC−4) in winter. India Standard Time stays on UTC+5:30 all year.
What is the best time for a meeting between AST and IST?
There is no 9-to-5 overlap; within an 8 AM–8 PM day the zones overlap for 3 hours 30 minutes on a weekday: 8:00 AM–11:30 AM ADT, which is 4:30 PM–8:00 PM IST.
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Related conversions
- IST to AST (reverse)
- EST to IST
- CST to IST
- MST to IST
- PST to IST
- UTC to IST
- GMT to IST
- CET to IST
- SGT to IST
- JST to IST
- AEST to IST
- AKST to IST
- All time zones
Computed from the IANA time zone database on Oct 23, 2026. Live clocks and the converter use your browser's copy of the same data.