IST to CST time conversion
CST is 11 hours 30 minutes behind IST.
CST is always UTC-6. Right now most places that use CST are on CDT (UTC-5): CDT is 10 hours 30 minutes behind IST.
Time difference with your location
IST is 5 hours 30 minutes ahead of UTC. Compare with your local time →
Choose a date and time
Choose the local time in IST to convert it to CST on that date.
Skipped clock-change times are unavailable; a repeated time uses its first occurrence.
24-hour conversion chart · IST → CST
This table converts each hour in IST to CST on 2026-10-21.
- Working hours
- Outside working hours
- Night hours
| IST | CST | Shared working hours |
|---|---|---|
| 00:0012:00 AM | 12:3012:30 PM -1 day | |
| 01:001:00 AM | 13:301:30 PM -1 day | |
| 02:002:00 AM | 14:302:30 PM -1 day | |
| 03:003:00 AM | 15:303:30 PM -1 day | |
| 04:004:00 AM | 16:304:30 PM -1 day | |
| 05:005:00 AM | 17:305:30 PM -1 day | |
| 06:006:00 AM | 18:306:30 PM -1 day | |
| 07:007:00 AM | 19:307:30 PM -1 day | |
| 08:008:00 AM | 20:308:30 PM -1 day | |
| 09:009:00 AM | 21:309:30 PM -1 day | |
| 10:0010:00 AM | 22:3010:30 PM -1 day | |
| 11:0011:00 AM | 23:3011:30 PM -1 day | |
| 12:0012:00 PM | 00:3012:30 AM | |
| 13:001:00 PM | 01:301:30 AM | |
| 14:002:00 PM | 02:302:30 AM | |
| 15:003:00 PM | 03:303:30 AM | |
| 16:004:00 PM | 04:304:30 AM | |
| 17:005:00 PM | 05:305:30 AM | |
| 18:006:00 PM | 06:306:30 AM | |
| 19:007:00 PM | 07:307:30 AM | |
| 20:008:00 PM | 08:308:30 AM | |
| 21:009:00 PM | 09:309:30 AM | |
| 22:0010:00 PM | 10:3010:30 AM | |
| 23:0011:00 PM | 11:3011:30 AM |
Quick conversion examples
These examples use IST (UTC+5:30) and CST (UTC-6); choosing a date applies the local clock changes.
Conversion formula: CST = IST − 11h30 · CDT = IST − 10h30.
| IST | CST |
|---|---|
| 6:00 AM IST | = 6:30 PM CST (-1 day) |
| 7:00 AM IST | = 7:30 PM CST (-1 day) |
| 8:00 AM IST | = 8:30 PM CST (-1 day) |
| 9:00 AM IST | = 9:30 PM CST (-1 day) |
| 10:00 AM IST | = 10:30 PM CST (-1 day) |
| 12:00 PM IST | = 12:30 AM CST |
| 3:00 PM IST | = 3:30 AM CST |
| 5:00 PM IST | = 5:30 AM CST |
| 6:00 PM IST | = 6:30 AM CST |
| 8:00 PM IST | = 8:30 AM CST |
Overlapping meeting hours
The 08:00–18:00 working days in IST and CST do not overlap on 2026-10-21.
Clock changes on both sides, 2026–2028
IST and CST have the following local clock changes in 2026–2028; all times in the table are local to that side.
| Year | IST | CST |
|---|---|---|
| 2026 | No clock changes; UTC+5:30 all year. | · 02:00 → 03:00 · 02:00 → 01:00 |
| 2027 | No clock changes; UTC+5:30 all year. | · 02:00 → 03:00 · 02:00 → 01:00 |
| 2028 | No clock changes; UTC+5:30 all year. | · 02:00 → 03:00 · 02:00 → 01:00 |
At the start of 2026, CST is 11 hours 30 minutes behind IST. The difference changes during the following periods.
- From 2026-03-08 13:30 IST until 2026-11-01 12:30 IST, CDT is 10 hours 30 minutes behind IST.
- From 2027-03-14 13:30 IST until 2027-11-07 12:30 IST, CDT is 10 hours 30 minutes behind IST.
- From 2028-03-12 13:30 IST until 2028-11-05 12:30 IST, CDT is 10 hours 30 minutes behind IST.
Frequently asked questions
What time is 9 AM IST in CST?
9:00 AM IST = 9:30 PM CST (-1 day), using UTC+5:30 and UTC-6. Choose a date above for the seasonal local time.
Does the time difference between IST and CST change during the year?
Yes. During 2026–2028: CST is 11 hours 30 minutes behind IST; CST is 10 hours 30 minutes behind IST. The clock-change table gives the dates for both sides.
How do I tell whether it is day or night in CST?
Read the CST clock above: this guide counts 06:00–18:00 local time as daytime and the rest as nighttime, without using sunrise and sunset.
What is the best time to call between IST and CST?
The 08:00–18:00 working days in IST and CST do not overlap.
What is the time difference between IST and CST now?
Right now, CST is 11 hours 30 minutes behind IST. Conversion formula: CST = IST − 11h30 · CDT = IST − 10h30.