Convert CST to IST
IST = CST +11 h 30 min
IST is 11 hours 30 minutes ahead of CST. CST is always UTC−6 and IST is always UTC+5:30, so this gap is the same on every date.
CST · Central Standard Time · UTC−6
5:05AM
Tuesday, November 3, 2026
IST · India Standard Time · UTC+5:30
4:35PM
Tuesday, November 3, 2026
Chicago is on CST (UTC−6) right now.
- Next clock change: March 14, 2027. Chicago moves to CDT (UTC−5), so India is then 10 hours 30 minutes ahead of Chicago.
- Next clock change: November 7, 2027. Chicago moves to CST (UTC−6), so India is then 11 hours 30 minutes ahead of Chicago.
CST to IST for every hour
Each IST column holds for part of the year (dates in the header for 2027). The first uses the fixed offsets (CST UTC−6, IST UTC+5:30); the others give local clock time when daylight saving time changes the gap. From 12:30 PM CST, IST is already on the next calendar day.
| CST | IST +11 h 30 minfixed offsets | IST +10 h 30 minMar 14 – Nov 7 | 24-hour |
|---|---|---|---|
| 12:00 AM | 11:30 AM | 10:30 AM | 00:00 → 11:30 |
| 1:00 AM | 12:30 PM | 11:30 AM | 01:00 → 12:30 |
| 2:00 AM | 1:30 PM | 12:30 PM | 02:00 → 13:30 |
| 3:00 AM | 2:30 PM | 1:30 PM | 03:00 → 14:30 |
| 4:00 AM | 3:30 PM | 2:30 PM | 04:00 → 15:30 |
| 5:00 AM | 4:30 PM | 3:30 PM | 05:00 → 16:30 |
| 6:00 AM | 5:30 PM | 4:30 PM | 06:00 → 17:30 |
| 7:00 AM | 6:30 PM | 5:30 PM | 07:00 → 18:30 |
| 8:00 AM | 7:30 PM | 6:30 PM | 08:00 → 19:30 |
| 9:00 AM | 8:30 PM | 7:30 PM | 09:00 → 20:30 |
| 10:00 AM | 9:30 PM | 8:30 PM | 10:00 → 21:30 |
| 11:00 AM | 10:30 PM | 9:30 PM | 11:00 → 22:30 |
| 12:00 PM | 11:30 PM | 10:30 PM | 12:00 → 23:30 |
| 1:00 PM | 12:30 AM +1 day | 11:30 PM | 13:00 → 00:30 |
| 2:00 PM | 1:30 AM +1 day | 12:30 AM +1 day | 14:00 → 01:30 |
| 3:00 PM | 2:30 AM +1 day | 1:30 AM +1 day | 15:00 → 02:30 |
| 4:00 PM | 3:30 AM +1 day | 2:30 AM +1 day | 16:00 → 03:30 |
| 5:00 PM | 4:30 AM +1 day | 3:30 AM +1 day | 17:00 → 04:30 |
| 6:00 PM | 5:30 AM +1 day | 4:30 AM +1 day | 18:00 → 05:30 |
| 7:00 PM | 6:30 AM +1 day | 5:30 AM +1 day | 19:00 → 06:30 |
| 8:00 PM | 7:30 AM +1 day | 6:30 AM +1 day | 20:00 → 07:30 |
| 9:00 PM | 8:30 AM +1 day | 7:30 AM +1 day | 21:00 → 08:30 |
| 10:00 PM | 9:30 AM +1 day | 8:30 AM +1 day | 22:00 → 09:30 |
| 11:00 PM | 10:30 AM +1 day | 9:30 AM +1 day | 23:00 → 10:30 |
Bold rows fall inside office hours (9:00 to 17:00) on both sides. The dot marks the current CST hour.
The CST times people look up most
| CST | IST +11 h 30 min | IST +10 h 30 min |
|---|---|---|
| 11:59 PM | 11:29 AM +1 day | 10:29 AM +1 day |
| 10:00 AM | 9:30 PM | 8:30 PM |
| 11:00 AM | 10:30 PM | 9:30 PM |
| 12:49 PM | 12:19 AM +1 day | 11:19 PM |
| 9:30 AM | 9:00 PM | 8:00 PM |
| 12:00 PM | 11:30 PM | 10:30 PM |
Does the difference change during the year?
As written, no: CST is always UTC−6 and IST is always UTC+5:30, so the gap is 11 hours 30 minutes on every date. But Chicago uses CST only in winter, and people often keep writing “CST” when they mean the local time. Between the local clocks of Chicago and India, the gap is 11 hours 30 minutes or 10 hours 30 minutes:
| From | What changes | Chicago | India | IST vs CST |
|---|---|---|---|---|
| January 1 | Start of the year | CST (UTC−6) | IST (UTC+5:30) | +11 h 30 min |
| March 8 | Chicago moves to CDT (UTC−5) | CDT (UTC−5) | IST (UTC+5:30) | +10 h 30 min |
| November 1 | Chicago moves to CST (UTC−6) | CST (UTC−6) | IST (UTC+5:30) | +11 h 30 min |
| From | What changes | Chicago | India | IST vs CST |
|---|---|---|---|---|
| January 1 | Start of the year | CST (UTC−6) | IST (UTC+5:30) | +11 h 30 min |
| March 14 | Chicago moves to CDT (UTC−5) | CDT (UTC−5) | IST (UTC+5:30) | +10 h 30 min |
| November 7 | Chicago moves to CST (UTC−6) | CST (UTC−6) | IST (UTC+5:30) | +11 h 30 min |
Converting CST to IST by hand
With the fixed offsets, add 11 hours 30 minutes: 3:30 PM CST is 3:00 AM IST (next day). In your head it is easier to swap AM and PM, then take away 30 minutes: 3:30 PM, 3:30 AM, 3:00 AM.
With the +10 h 30 min gap (Mar 14 – Nov 7), add 10 hours 30 minutes: 3:30 PM CST is 2:00 AM IST (next day). In your head it is easier to swap AM and PM, then take away 1 hour 30 minutes: 3:30 PM, 3:30 AM, 2:00 AM.
Going back from IST to CST, do the opposite: the IST to CST page has its own table.
Where the CST and IST working days overlap
CST to IST (+11 h 30 min): Two 9:00–17:00 days do not overlap at all. To meet between 7:00 AM and 9:00 PM on both sides, start at 7:00 AM to 9:00 AM CST (6:30 PM to 8:30 PM IST), or 8:00 PM to 9:00 PM CST (7:30 AM to 8:30 AM IST).
+10 h 30 min (between Mar 14 and Nov 7, 2027): Two 9:00–17:00 days do not overlap at all. To meet between 7:00 AM and 9:00 PM on both sides, start at 7:00 AM to 10:00 AM CST (5:30 PM to 8:30 PM IST), or 9:00 PM CST (7:30 AM IST).
A meeting fixed in one city’s calendar moves by an hour for the other when the gap changes. Calendar apps handle this when the event is saved in a named zone (for example America/Chicago) rather than as a fixed offset.
What CST and IST mean
Central Standard Time
CST here is North American Central Standard Time, UTC−6: winter time in Chicago, Houston and Dallas, and all-year time in Mexico City, most of Central America and Saskatchewan. Since 2026 Alberta and the Northwest Territories also stay on UTC−6 all year.
CST can also mean China Standard Time (UTC+8, China) or Cuba Standard Time (UTC−5, Cuba). This page uses Central Standard Time, the meaning people searching for this conversion have in mind. For another one, type the city into the time zone converter.
India Standard Time
IST here is India Standard Time, UTC+5:30, used in all of India all year: no daylight saving time and a single zone for the whole country.
IST can also mean Israel Standard Time (UTC+2, Israel) or Irish Standard Time (UTC+1, Ireland, in summer). This page uses India Standard Time, the meaning people searching for this conversion have in mind. For another one, type the city into the time zone converter.