AST to IST: AST is 8 hours 30 minutes behind IST
Atlantic Time is 8 hours 30 minutes behind India Standard Time right now. It is 10:04 pm ADT in Atlantic and 6:34 am IST in India, which is already the next day there.
Convert a specific time from AST to IST
Pick any time and date to convert it both ways. The conversion runs in your browser against the real zone rules, so a date inside a daylight saving period gets that period's offset rather than today's.
What is the time difference between AST and IST?
India Standard Time is 8 hours 30 minutes ahead of Atlantic Time. To go from AST to IST you add 8 hours 30 minutes. That gap is not fixed. Across 2026 the distance between these two zones takes 2 different values, from 8 hours 30 minutes to 9 hours 30 minutes, because Atlantic moves its clocks and India does not. This page recomputes it rather than assuming.
AST to IST conversion table
Every hour of Thursday, September 24, 2026 in Atlantic, with the matching reading in India. 8 of the 24 hours land on a different calendar date in India, which is the part people get wrong when they schedule across this pair.
| AST | AST 24h | IST | IST 24h | Date |
|---|---|---|---|---|
| 12:00 am | 00:00 | 8:30 am | 08:30 | same day |
| 1:00 am | 01:00 | 9:30 am | 09:30 | same day |
| 2:00 am | 02:00 | 10:30 am | 10:30 | same day |
| 3:00 am | 03:00 | 11:30 am | 11:30 | same day |
| 4:00 am | 04:00 | 12:30 pm | 12:30 | same day |
| 5:00 am | 05:00 | 1:30 pm | 13:30 | same day |
| 6:00 am | 06:00 | 2:30 pm | 14:30 | same day |
| 7:00 am | 07:00 | 3:30 pm | 15:30 | same day |
| 8:00 am | 08:00 | 4:30 pm | 16:30 | same day |
| 9:00 am | 09:00 | 5:30 pm | 17:30 | same day |
| 10:00 am | 10:00 | 6:30 pm | 18:30 | same day |
| 11:00 am | 11:00 | 7:30 pm | 19:30 | same day |
| 12:00 pm | 12:00 | 8:30 pm | 20:30 | same day |
| 1:00 pm | 13:00 | 9:30 pm | 21:30 | same day |
| 2:00 pm | 14:00 | 10:30 pm | 22:30 | same day |
| 3:00 pm | 15:00 | 11:30 pm | 23:30 | same day |
| 4:00 pm | 16:00 | 12:30 am | 00:30 | the next day |
| 5:00 pm | 17:00 | 1:30 am | 01:30 | the next day |
| 6:00 pm | 18:00 | 2:30 am | 02:30 | the next day |
| 7:00 pm | 19:00 | 3:30 am | 03:30 | the next day |
| 8:00 pm | 20:00 | 4:30 am | 04:30 | the next day |
| 9:00 pm | 21:00 | 5:30 am | 05:30 | the next day |
| 10:00 pm | 22:00 | 6:30 am | 06:30 | the next day |
| 11:00 pm | 23:00 | 7:30 am | 07:30 | the next day |
What are the best hours to schedule a call between AST and IST?
No hour of the standard 9:00 am to 5:00 pm working day falls inside working hours on both sides. Atlantic and India are 8 hours 30 minutes apart, which is too far for an overlap, so somebody has to take a call outside their own working day. The least painful options are below, ranked by how close both sides sit to the middle of the afternoon.
| AST | IST | Working hours | Note |
|---|---|---|---|
| 7:00 am | 3:30 pm | IST only | early morning in Atlantic, afternoon in India |
| 8:00 am | 4:30 pm | IST only | mid morning in Atlantic, afternoon in India |
| 9:00 am | 5:30 pm | AST only | mid morning in Atlantic, evening in India |
Does daylight saving change AST to IST?
Atlantic Time is currently on ADT and changes next on Sunday, November 1, 2026, when the clock falls back from 1:59 am to 1:00 am and the offset moves from UTC-3 to UTC-4.
India Standard Time does not move its clocks at all, so its UTC+5:30 offset holds every day of the year.
Because the two sides do not move together, the answer to this conversion changes during the year. For part of the year the gap is 8 hours 30 minutes and for the rest it is 9 hours 30 minutes. The table above is built for today, not for an average day.
Is AST ahead of or behind IST?
AST is behind IST by 8 hours 30 minutes: when it is 12:00 pm in Atlantic, it is 8:30 pm in India. One wrinkle worth knowing: AST and ADT are two names for the same zone, not two zones. Atlantic Time reads AST in winter and ADT in summer. When somebody types "ast to ist" they nearly always mean the zone rather than the literal winter offset, so this page resolves AST to America/Halifax and IST to Asia/Kolkata and applies whichever offset is genuinely in force on the day.
Atlantic Time covers Halifax, Moncton and the Canadian Maritimes. India Standard Time covers the whole of India on a single half hour offset. The identifiers behind them are America/Halifax and Asia/Kolkata, which is what any calendar or scheduling system should be storing rather than a fixed number of hours.
Questions
- What is AST in IST?
- AST is 8 hours 30 minutes behind IST. 9:00 am AST is 5:30 pm IST.
- How many hours ahead is IST of AST?
- IST is 8 hours 30 minutes ahead of AST. That varies across the year, between 8 hours 30 minutes and 9 hours 30 minutes.
- What time is it in India right now?
- 6:34 am IST on Friday, September 25, 2026.
- When can Atlantic and India meet during working hours?
- There is no shared working hour. The closest fit is 7:00 am AST, which is 3:30 pm IST.
- Does this account for daylight saving?
- Yes. Every reading is computed from the IANA database for the actual date, so ADT and IST are the abbreviations genuinely in force today rather than a fixed assumption.
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