This IST to CST converter turns any time in India Standard Time (IST) into Central Standard Time (CST), using your device clock so daylight saving is applied automatically. CST is 11 hours 30 minutes behind IST when both zones are on standard time, and 10 hours 30 minutes behind during the summer months when clocks have shifted. IST is UTC+5:30; CST is UTC−6 (CDT: UTC−5).
IST covers Mumbai, Delhi, Bengaluru; CST covers Chicago, Dallas, Houston. Because only CST observes daylight saving time, the difference is not constant through the year. The tables below show both cases, and the converter at the top always uses the rule in force on the date you pick.
IST and CST UTC offsets
IST
UTC+5:30
India Standard Time
No daylight saving time
CST
UTC−6
Central Standard Time
CDT UTC−5 from March 8 to November 1, 2026
IST to CST conversion table (standard time)
| IST | CST |
|---|---|
| 12 am | 12:30 pmprevious day |
| 3 am | 3:30 pmprevious day |
| 6 am | 6:30 pmprevious day |
| 8 am | 8:30 pmprevious day |
| 9 am | 9:30 pmprevious day |
| 10 am | 10:30 pmprevious day |
| 11 am | 11:30 pmprevious day |
| 12 pm | 12:30 am |
| 1 pm | 1:30 am |
| 2 pm | 2:30 am |
| 3 pm | 3:30 am |
| 4 pm | 4:30 am |
| 5 pm | 5:30 am |
| 6 pm | 6:30 am |
| 8 pm | 8:30 am |
| 10 pm | 10:30 am |
IST to CST during daylight saving
Between the dates listed above, the difference is 10 hours 30 minutes instead of 11 hours 30 minutes.
| IST | CST/CDT |
|---|---|
| 12 am | 1:30 pmprevious day |
| 3 am | 4:30 pmprevious day |
| 6 am | 7:30 pmprevious day |
| 8 am | 9:30 pmprevious day |
| 9 am | 10:30 pmprevious day |
| 10 am | 11:30 pmprevious day |
| 11 am | 12:30 am |
| 12 pm | 1:30 am |
| 1 pm | 2:30 am |
| 2 pm | 3:30 am |
| 3 pm | 4:30 am |
| 4 pm | 5:30 am |
| 5 pm | 6:30 am |
| 6 pm | 7:30 am |
| 8 pm | 9:30 am |
| 10 pm | 11:30 am |
Frequently asked questions
What is the time difference between IST and CST?
CST is 11 hours 30 minutes behind IST on standard time. During daylight saving the gap changes to 10 hours 30 minutes. That comes from the UTC offsets: IST is UTC+5:30 and CST is UTC−6. For example, 9 am IST = 9:30 pm CST the previous day, and in summer 9 am IST = 10:30 pm CST the previous day.
Is CST ahead of or behind IST?
CST is 11 hours 30 minutes behind IST, so when it is noon in IST it is 12:30 am in CST. Ahead means the clock there already shows a later time; a call at 5 pm IST lands at 5:30 am CST.
Does IST or CST observe daylight saving time in 2026?
IST keeps UTC+5:30 all year. CST switches to CDT (UTC−5) on March 8 and back on November 1. Between those dates the difference in the table above shifts by an hour, which is the usual cause of missed calls in spring and autumn.
What is the best time for a meeting between IST and CST?
Office hours (9 am to 5 pm) do not overlap at all with a 11 hours 30 minutes difference. The least painful options are early morning in CST or early evening in IST; for example 8 am IST = 8:30 pm CST the previous day and 6 pm IST = 6:30 am CST. Rotate the inconvenient slot between the two sides for recurring calls.
Which cities use IST and CST?
IST (India Standard Time) is used in Mumbai, Delhi, Bengaluru, Kolkata. CST (Central Standard Time) is used in Chicago, Dallas, Houston, Mexico City (no DST). Some cities inside a zone skip daylight saving, noted in parentheses, so their offset matches only part of the year.