IST to CST converter
Convert Indian Standard Time to Central Time. Chicago is 11.5 hours behind India in winter (CST) and 10.5 hours behind in summer (CDT).
Chicago is 11 hours 30 minutes behind India (IST vs CST).
From India to the US Midwest
Starting from India and finding Chicago means subtracting eleven and a half hours in winter and ten and a half in summer. 9:00 AM IST is 9:30 PM CST the previous evening, and 9:00 PM IST is 9:30 AM CST the same day.
Indian teams working with Midwest clients use this conversion to plan evening shifts. The Chicago morning is the only common ground, which is the Indian late evening.
The Indian evening is the shared window for most calls.
Evening shifts and client calls
Indian teams working with Chicago clients start late and finish at night.
- 7:30 PM IST is 8:00 AM CST
- 9:30 PM IST is 10:00 AM CST
- 8:30 PM IST is 9:00 AM CST
The shift is shorter in summer, when the gap is 10.5 hours.
Exams, admissions and applications
Indian students applying to Midwest universities need to check the deadline time zone.
- A deadline of 11:59 PM CST is 11:29 AM IST the next day
- A 5:00 PM CST deadline is 4:30 AM IST the next day
- An interview at 10:00 AM CST is 9:30 PM IST
Check whether the deadline is on the previous or next Indian date.
Shopping and shipping
Orders placed in India during the day arrive in Chicago at night.
- A purchase at 10:00 AM IST is logged at 10:30 PM CST the evening before
- A package promised by 5 PM CST needs to leave by 4:30 AM IST
- A customer service call at 9 PM IST is at 9:30 AM CST
A same-day dispatch from India is next-day for Chicago.
Chicago deadlines for Indian readers
A Chicago deadline of 5:00 PM CST is 4:30 AM IST the next day. A deadline at 11:59 PM CST is 11:29 AM IST on the next date, which means Indian applicants can work through their night.
An Indian deadline of 5:00 PM IST is 5:30 AM CST the same day. Chicago colleagues should plan to finish before they go to bed the night before.
Why the figure changes with the US season
India stays on IST all year. Chicago changes from CST to CDT on the second Sunday of March and back on the first Sunday of November. The gap is therefore 11.5 hours in winter and 10.5 hours in summer.
- Mar 14, 2027: Chicago moves to CDT (UTC−5); the gap becomes 10 hours 30 minutes
- Nov 7, 2027: Chicago moves to CST (UTC−6); the gap becomes 11 hours 30 minutes
Look out for the first weeks after each US change: a call that was at 9:30 PM IST the week before can be 8:30 PM IST (or 10:30 PM) if Chicago holds the time constant.
India to Chicago, every hour
Times are for Nov 6, 2026, when Chicago is 11 hours 30 minutes behind India. The gap changes on the dates listed above. Green rows are the hours when both places are inside a 9-to-5 day.
| India (IST) | ChicagoCST, −11.5 hrs |
|---|---|
| 12:00 AM (midnight) | 12:30 PM previous day |
| 1:00 AM | 1:30 PM previous day |
| 2:00 AM | 2:30 PM previous day |
| 3:00 AM | 3:30 PM previous day |
| 4:00 AM | 4:30 PM previous day |
| 5:00 AM | 5:30 PM previous day |
| 6:00 AM | 6:30 PM previous day |
| 7:00 AM | 7:30 PM previous day |
| 8:00 AM | 8:30 PM previous day |
| 9:00 AM | 9:30 PM previous day |
| 10:00 AM | 10:30 PM previous day |
| 11:00 AM | 11:30 PM previous day |
| 12:00 PM (noon) | 12:30 AM |
| 1:00 PM | 1:30 AM |
| 2:00 PM | 2:30 AM |
| 3:00 PM | 3:30 AM |
| 4:00 PM | 4:30 AM |
| 5:00 PM | 5:30 AM |
| 6:00 PM | 6:30 AM |
| 7:00 PM | 7:30 AM |
| 8:00 PM | 8:30 AM |
| 9:00 PM | 9:30 AM |
| 10:00 PM | 10:30 AM |
| 11:00 PM | 11:30 AM |
“next day” and “previous day” mean Chicago is on a different calendar date from India.
Quick answers
What time is 9 AM IST in Chicago?
9:30 PM CST the previous evening (8:30 PM CDT in summer).
Is Chicago ahead of India?
No. Chicago is 11.5 hours behind in winter and 10.5 hours behind in summer.
What is 9 PM IST in CST?
9:30 AM CST.
When is the best time for an Indian team to call Chicago?
Between 7:30 and 10:30 PM IST, which is 8 AM to 11 AM in Chicago.
Does the gap between India and Chicago change?
Yes, by one hour, when the US changes its clocks in March and November.