India Standard Time (IST) is currently 10.5 hours ahead of Central Daylight Time (CST). Convert any IST time to CST instantly — DST-aware, live clock, and best meeting hours included.
IST is known as India Standard Time. CST is known as Central Daylight Time. IST is 10.5 hours ahead of CST. So, when it is 12:00 AM in IST, it is 1:30 PM in CST.
Common IST times and their CST equivalents.
| IST Time | CST Time |
|---|---|
| 12:00 AM IST | 1:30 PM CST |
| 1:00 AM IST | 2:30 PM CST |
| 2:00 AM IST | 3:30 PM CST |
| 3:00 AM IST | 4:30 PM CST |
| 4:00 AM IST | 5:30 PM CST |
| 5:00 AM IST | 6:30 PM CST |
| 6:00 AM IST | 7:30 PM CST |
| 7:00 AM IST | 8:30 PM CST |
| 8:00 AM IST | 9:30 PM CST |
| 9:00 AM IST | 10:30 PM CST |
| 10:00 AM IST | 11:30 PM CST |
| 11:00 AM IST | 12:30 AM CST |
| 12:00 PM IST | 1:30 AM CST |
| 1:00 PM IST | 2:30 AM CST |
| 2:00 PM IST | 3:30 AM CST |
| 3:00 PM IST | 4:30 AM CST |
| 4:00 PM IST | 5:30 AM CST |
| 5:00 PM IST | 6:30 AM CST |
| 6:00 PM IST | 7:30 AM CST |
| 7:00 PM IST | 8:30 AM CST |
| 8:00 PM IST | 9:30 AM CST |
| 9:00 PM IST | 10:30 AM CST |
| 10:00 PM IST | 11:30 AM CST |
| 11:00 PM IST | 12:30 PM CST |
India uses India Standard Time (IST, UTC+5:30) year-round with no Daylight Saving Time. The unusual 30-minute offset from UTC reflects a compromise made during India's unification — the country spans two natural time zone widths but uses a single zone for national cohesion. IST applies to all Indian cities including Delhi, Mumbai, Bangalore, Chennai, Kolkata, and Hyderabad.
Chicago uses Central Time — Central Standard Time (CST, UTC−6) in winter and Central Daylight Time (CDT, UTC−5) in summer, shifting on the same US DST schedule. It sits one hour behind Eastern Time and two hours ahead of Pacific, placing it in the heart of US business scheduling overlap.
Both IST and CST may observe Daylight Saving Time, which means the offset between them can change twice a year. Here is what to expect each season.
| Period | Note | IST | CST | Offset |
|---|---|---|---|---|
| Nov – Mar | Both on standard time | GMT+5:30 (UTC+5:30) | CST (UTC−6) | 11.5 hours |
| Mar – late Mar | US clocks forward, some zones still on standard | GMT+5:30 (UTC+5:30) | CDT (UTC−5) | 10.5 hours |
| Late Mar – Oct current | Both on summer / daylight time | GMT+5:30 (UTC+5:30) | CDT (UTC−5) | 10.5 hours |
| Late Oct – early Nov | Clocks transitioning — check exact date | GMT+5:30 (UTC+5:30) | CST (UTC−6) | 11.5 hours |
The transition window typically lasts 1–2 weeks in spring and autumn. If you have a recurring weekly meeting near a clock change, verify the exact date to avoid a missed call.
IST is currently 10.5 hours ahead of CST. IST uses India Standard Time (UTC+5:30) and CST uses Central Daylight Time (UTC−5).
IST and CST have no standard 9 am–6 pm business-hour overlap. Consider scheduling during early morning or late evening, or use a rotating schedule to share the inconvenience.
When it is 9:00 AM in IST, it is 10.5:00 pm in CST (previous day). IST is 10.5 hours ahead of CST.
When it is 5:00 PM in CST, it is 3.5:00 am in IST (next day).
CST observes Daylight Saving Time but IST does not. This means the offset between the two cities changes by one hour when CST transitions its clocks. Always verify the current offset when scheduling meetings near DST transition dates.