CST to IST Converter
IST is 11 hours 30 minutes ahead of CST. During US CDT (summer), the gap narrows to 10 hours 30 minutes. 9:00 AM CST is 8:30 PM in India, and 9:00 AM CDT is 7:30 PM.
Common Central Clock Times in India
Most searches for this conversion are for a single clock time. The common ones, on CST and on CDT:
| Central time | India time |
|---|---|
| 7:30 AM | 7:00 PM on CST, 6:00 PM on CDT |
| 8:00 AM | 7:30 PM on CST, 6:30 PM on CDT |
| 8:30 AM | 8:00 PM on CST, 7:00 PM on CDT |
| 9:00 AM | 8:30 PM on CST, 7:30 PM on CDT |
| 9:30 AM | 9:00 PM on CST, 8:00 PM on CDT |
| 10:00 AM | 9:30 PM on CST, 8:30 PM on CDT |
| 10:30 AM | 10:00 PM on CST, 9:00 PM on CDT |
| 11:00 AM | 10:30 PM on CST, 9:30 PM on CDT |
| 1:00 PM | 12:30 AM the next day on CST, 11:30 PM on CDT |
| 2:00 PM | 1:30 AM the next day on CST, 12:30 AM the next day on CDT |
| 4:00 PM | 3:30 AM the next day on CST, 2:30 AM the next day on CDT |
| 9:00 PM | 8:30 AM the next day on CST, 7:30 AM the next day on CDT |
Add 11 hours 30 minutes on CST and 10 hours 30 minutes on CDT. From 12:30 PM Central on CST (1:30 PM on CDT) the India time is already the next day.
CST to IST, Every Hour
Full 24-hour reference table. Use the live clocks above for the exact current offset.
| 🇺🇸 CST/CDT | 🇮🇳 CST → ISTUTC-6 to UTC+5:30, US standard time | 🇮🇳 CDT → ISTUTC-5 to UTC+5:30, US daylight time |
|---|---|---|
| 00:00 | 11:30 AM | 10:30 AM |
| 01:00 | 12:30 PM | 11:30 AM |
| 02:00 | 1:30 PM | 12:30 PM |
| 03:00 | 2:30 PM | 1:30 PM |
| 04:00 | 3:30 PM | 2:30 PM |
| 05:00 | 4:30 PM | 3:30 PM |
| 06:00 | 5:30 PM | 4:30 PM |
| 07:00 | 6:30 PM | 5:30 PM |
| 08:00 | 7:30 PM | 6:30 PM |
| 09:00 | 8:30 PM | 7:30 PM |
| 10:00 | 9:30 PM | 8:30 PM |
| 11:00 | 10:30 PM | 9:30 PM |
| 12:00 | 11:30 PM | 10:30 PM |
| 13:00 | 12:30 AMnext day | 11:30 PM |
| 14:00 | 1:30 AMnext day | 12:30 AMnext day |
| 15:00 | 2:30 AMnext day | 1:30 AMnext day |
| 16:00 | 3:30 AMnext day | 2:30 AMnext day |
| 17:00 | 4:30 AMnext day | 3:30 AMnext day |
| 18:00 | 5:30 AMnext day | 4:30 AMnext day |
| 19:00 | 6:30 AMnext day | 5:30 AMnext day |
| 20:00 | 7:30 AMnext day | 6:30 AMnext day |
| 21:00 | 8:30 AMnext day | 7:30 AMnext day |
| 22:00 | 9:30 AMnext day | 8:30 AMnext day |
| 23:00 | 10:30 AMnext day | 9:30 AMnext day |
* "next day" = converted time falls on the following calendar day.
A Central Morning, an India Evening
No hour is inside a 9-to-5 day on both sides. The closest is the start of the Central day, which is the end of the India day: 8:00 to 9:30 AM Central is 7:30 PM to 9:00 PM in India on CST and 6:30 PM to 8:00 PM on CDT. The other slot is a Central evening, which is the India morning of the next day.
| Central Standard Time | India Standard Time |
|---|---|
| 8:00 AM–9:30 AM | 7:30 PM–9:00 PM |
| CST → IST: Central Standard Time: partly outside 9 AM–5 PM. India Standard Time: after 5 PM. A Central morning that lands in the India evening. | |
| 8:00 AM–9:30 AM | 6:30 PM–8:00 PM |
| CDT → IST: Central Standard Time: partly outside 9 AM–5 PM. India Standard Time: after 5 PM. The same Central hours, an hour earlier in India. | |
| 8:30 PM–10:00 PM | 8:00 AM–9:30 AMnext day |
| CST → IST: Central Standard Time: after 5 PM. India Standard Time: partly outside 9 AM–5 PM. A Central evening that lands in the India morning of the next day. | |
| 9:30 PM–10:30 PM | 8:00 AM–9:00 AMnext day |
| CDT → IST: Central Standard Time: after 5 PM. India Standard Time: before 9 AM. The same India morning, an hour later in Central Time. | |
"Inside 9 AM–5 PM" is a planning assumption for a standard office day on each side, not a claim about any company's hours.
Not Every Central Place Has the Same Gap
India is UTC+5:30 all year, so the gap changes only with the western end:
| Place | India is ahead by |
|---|---|
| Chicago, Dallas, Houston, Minneapolis | 11 hours 30 minutes on CST, 10 hours 30 minutes on CDT |
| Regina (Saskatchewan, no clock change) | 11 hours 30 minutes, all year |
| Mexico City (no clock change since 2022) | 11 hours 30 minutes, all year |
| Winnipeg (Manitoba, fixed from November 1, 2026) | 10 hours 30 minutes, all year |
Manitoba has decided to stay on summer time from November 1, 2026, so from then on Winnipeg is on the CDT gap in winter too.
CST Is Often Written When CDT Is Meant
CST is the winter label, from the first Sunday in November to the second Sunday in March. For the other eight months Chicago and Dallas are on CDT, even though many people keep writing "CST". An invite that says "9:00 AM CST" in July usually means Central time, and the India time is 7:30 PM, not 8:30 PM. If you are unsure, use the CDT column between March and early November.
Going the other way, India's 9:00 AM is 9:30 PM the previous day Central on CST and 10:30 PM the previous day on CDT, and India's 6:00 PM is 6:30 AM Central on CST and 7:30 AM on CDT. The same three letters also name China Standard Time (UTC+8), so an invite from outside the US that says only "CST" needs a city.
A Chicago Team and an India Deadline
Say a Chicago team needs an answer from India by the end of the India day. India's 6:00 PM finish is 6:30 AM in Central Time while it is on CST, and 7:30 AM while it is on CDT, so a question sent after 6:30 AM Central in winter reaches India once the working day has ended.
The other direction is kinder. A message sent from Chicago at 8:00 PM arrives at 7:30 AM the next day on CST and 6:30 AM the next day on CDT, early in the India morning, before most of the India team has started. India does not change its clocks and Central Time does, which is why the same Chicago hour moves by one hour in March and November.
Write both zones next to the time in every invite. "CT" alone does not tell the India side whether it is CST or CDT on that date.