ACST to IST: ACST is 4 hours ahead of IST
Australian Central Time is 4 hours ahead of India Standard Time right now. It is 9:30 am ACST in Australian Central and 5:30 am IST in India.
Convert a specific time from ACST 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 ACST and IST?
India Standard Time is 4 hours behind Australian Central Time. To go from ACST to IST you subtract 4 hours. That gap is not fixed. Across 2026 the distance between these two zones takes 2 different values, from 4 hours to 5 hours, because Australian Central moves its clocks and India does not. This page recomputes it rather than assuming.
ACST to IST conversion table
Every hour of Friday, September 25, 2026 in Australian Central, with the matching reading in India. 4 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.
| ACST | ACST 24h | IST | IST 24h | Date |
|---|---|---|---|---|
| 12:00 am | 00:00 | 8:00 pm | 20:00 | the previous day |
| 1:00 am | 01:00 | 9:00 pm | 21:00 | the previous day |
| 2:00 am | 02:00 | 10:00 pm | 22:00 | the previous day |
| 3:00 am | 03:00 | 11:00 pm | 23:00 | the previous day |
| 4:00 am | 04:00 | 12:00 am | 00:00 | same day |
| 5:00 am | 05:00 | 1:00 am | 01:00 | same day |
| 6:00 am | 06:00 | 2:00 am | 02:00 | same day |
| 7:00 am | 07:00 | 3:00 am | 03:00 | same day |
| 8:00 am | 08:00 | 4:00 am | 04:00 | same day |
| 9:00 am | 09:00 | 5:00 am | 05:00 | same day |
| 10:00 am | 10:00 | 6:00 am | 06:00 | same day |
| 11:00 am | 11:00 | 7:00 am | 07:00 | same day |
| 12:00 pm | 12:00 | 8:00 am | 08:00 | same day |
| 1:00 pm | 13:00 | 9:00 am | 09:00 | same day |
| 2:00 pm | 14:00 | 10:00 am | 10:00 | same day |
| 3:00 pm | 15:00 | 11:00 am | 11:00 | same day |
| 4:00 pm | 16:00 | 12:00 pm | 12:00 | same day |
| 5:00 pm | 17:00 | 1:00 pm | 13:00 | same day |
| 6:00 pm | 18:00 | 2:00 pm | 14:00 | same day |
| 7:00 pm | 19:00 | 3:00 pm | 15:00 | same day |
| 8:00 pm | 20:00 | 4:00 pm | 16:00 | same day |
| 9:00 pm | 21:00 | 5:00 pm | 17:00 | same day |
| 10:00 pm | 22:00 | 6:00 pm | 18:00 | same day |
| 11:00 pm | 23:00 | 7:00 pm | 19:00 | same day |
What are the best hours to schedule a call between ACST and IST?
4 hours of the standard 9:00 am to 5:00 pm working day line up in both zones, from 1:00 pm ACST to 5:00 pm ACST. In India that window reads 9:00 am to 1:00 pm. Outside it, one side is either not yet at their desk or already gone.
| ACST | IST | Working hours | Note |
|---|---|---|---|
| 1:00 pm | 9:00 am | both sides | afternoon in Australian Central, mid morning in India |
| 2:00 pm | 10:00 am | both sides | afternoon in Australian Central, mid morning in India |
| 3:00 pm | 11:00 am | both sides | afternoon in Australian Central, mid morning in India |
| 4:00 pm | 12:00 pm | both sides | afternoon in Australian Central, noon in India |
Does daylight saving change ACST to IST?
Australian Central Time is currently on ACST and changes next on Sunday, October 4, 2026, when the clock jumps forward from 1:59 am to 3:00 am and the offset moves from UTC+9:30 to UTC+10:30.
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 4 hours and for the rest it is 5 hours. The table above is built for today, not for an average day.
Is ACST ahead of or behind IST?
ACST is ahead of IST by 4 hours: when it is 12:00 pm in Australian Central, it is 8:00 am in India. One wrinkle worth knowing: ACST and ACDT are two names for the same zone, not two zones. Australian Central Time reads ACST in winter and ACDT in summer. When somebody types "acst to ist" they nearly always mean the zone rather than the literal winter offset, so this page resolves ACST to Australia/Adelaide and IST to Asia/Kolkata and applies whichever offset is genuinely in force on the day.
Australian Central Time covers Adelaide and South Australia, on a half hour offset that also shifts for summer. India Standard Time covers the whole of India on a single half hour offset. The identifiers behind them are Australia/Adelaide and Asia/Kolkata, which is what any calendar or scheduling system should be storing rather than a fixed number of hours.
Questions
- What is ACST in IST?
- ACST is 4 hours ahead of IST. 9:00 am ACST is 5:00 am IST.
- How many hours ahead is IST of ACST?
- IST is 4 hours behind ACST. That varies across the year, between 4 hours and 5 hours.
- What time is it in India right now?
- 5:30 am IST on Friday, September 25, 2026.
- When can Australian Central and India meet during working hours?
- Between 1:00 pm and 5:00 pm ACST, which is 9:00 am to 1:00 pm IST.
- Does this account for daylight saving?
- Yes. Every reading is computed from the IANA database for the actual date, so ACST and IST are the abbreviations genuinely in force today rather than a fixed assumption.
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