Time ZonesThe time difference
Chicago is 11 hours 30 minutes behind India for part of the year and 10 hours 30 minutes behind for the rest, because Chicago changes its clocks and India does not. India is always UTC+5:30, known as IST.
Which difference applies when
- 1 January 2026 to 8 March 2026: Chicago is 11 hours 30 minutes behind India (UTC−6).
- From 8 March 2026 to 1 November 2026: Chicago is 10 hours 30 minutes behind India (UTC−5).
- From 1 November 2026 to 14 March 2027: Chicago is 11 hours 30 minutes behind India (UTC−6).
- From 14 March 2027 to 7 November 2027: Chicago is 10 hours 30 minutes behind India (UTC−5).
- From 7 November 2027 to 31 December 2027: Chicago is 11 hours 30 minutes behind India (UTC−6).
India time to Chicago time when Chicago is UTC−6
Good hours to start a call (8 am to 9 pm in both places): from 8:00 am to 8:00 pm India time. Hours that start inside office time (9 am to 6 pm) in both: none, so one side has to start early or stay late.
| India (IST) | Chicago |
|---|---|
| 12:00 am | 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 | 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 |
India time to Chicago time when Chicago is UTC−5
Good hours to start a call (8 am to 9 pm in both places): from 7:00 pm to 8:00 pm India time. Hours that start inside office time (9 am to 6 pm) in both: none, so one side has to start early or stay late.
| India (IST) | Chicago |
|---|---|
| 12:00 am | 1:30 pm previous day |
| 1:00 am | 2:30 pm previous day |
| 2:00 am | 3:30 pm previous day |
| 3:00 am | 4:30 pm previous day |
| 4:00 am | 5:30 pm previous day |
| 5:00 am | 6:30 pm previous day |
| 6:00 am | 7:30 pm previous day |
| 7:00 am | 8:30 pm previous day |
| 8:00 am | 9:30 pm previous day |
| 9:00 am | 10:30 pm previous day |
| 10:00 am | 11:30 pm previous day |
| 11:00 am | 12:30 am |
| 12:00 pm | 1:30 am |
| 1:00 pm | 2:30 am |
| 2:00 pm | 3:30 am |
| 3:00 pm | 4:30 am |
| 4:00 pm | 5:30 am |
| 5:00 pm | 6:30 am |
| 6:00 pm | 7:30 am |
| 7:00 pm | 8:30 am |
| 8:00 pm | 9:30 am |
| 9:00 pm | 10:30 am |
| 10:00 pm | 11:30 am |
| 11:00 pm | 12:30 pm |
Worked examples
While Chicago is UTC−6. An office that closes at 6:00 pm in India closes when it is 6:30 am in Chicago. A 9:00 am start in Chicago is 8:30 pm in India, and its 6:00 pm finish is 5:30 am the next day in India. A message sent at 10:30 pm from India lands at 11:00 am in Chicago.
While Chicago is UTC−5. An office that closes at 6:00 pm in India closes when it is 7:30 am in Chicago. A 9:00 am start in Chicago is 7:30 pm in India, and its 6:00 pm finish is 4:30 am the next day in India. A message sent at 10:30 pm from India lands at 12:00 pm in Chicago.
When the date is different
Chicago is behind India (while Chicago is UTC−6), so for 11 hours 30 minutes of every day the calendar date differs: from midnight until 11:30 am India time, it is still the previous day in Chicago. Mention the date as well as the time when you fix something in those hours.
Chicago is behind India (while Chicago is UTC−5), so for 10 hours 30 minutes of every day the calendar date differs: from midnight until 10:30 am India time, it is still the previous day in Chicago. Mention the date as well as the time when you fix something in those hours.
Why the gap is what it is
Indian Standard Time follows the sun at longitude 82.5° east. The zone that Chicago belongs to has its largest city, Chicago, at about 87.7° west. The sun crosses the sky between those two lines in about 11 hours 21 minutes. Clock time rounds that to a tidy figure: 11 hours 30 minutes or 10 hours 30 minutes. The two figures differ because every country picks a round offset that suits its whole territory, and some add summer time on top.
Rows marked in colour fall between 8 am and 9 pm in both places. Dates are from the IANA time zone database 2026f.
More
Read about time in Chicago or time in India. Other conversions from India: New York, Denver, Los Angeles, Toronto, London, Paris, Berlin, Moscow, Dubai, Riyadh, Doha, Kuwait, Karachi, Kathmandu, Dhaka, Colombo, Singapore, Kuala Lumpur, Bangkok, Hong Kong, Shanghai, Tokyo, Seoul, Sydney, Melbourne, Perth, Auckland, Johannesburg, Nairobi.