COT to IST Time Converter
IST is 10 hours and 30 minutes ahead of COT. COT is UTC-5:00, and IST is UTC+5:30.
Best Time to Call Between COT and IST
Standard 9-to-5 hours in these two zones never overlap, so someone has to take the call outside their working day. The most workable window is 7:00 AM to 12:00 PM COT, which is 5:30 PM to 10:30 PM IST.
both at work COT only IST only neither — hours along the strip are COT.
Common Times Converted
COT on the left, IST on the right.
COT to IST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| COT | IST | Working hours |
|---|---|---|
| 12:00 AM | 10:30 AM | IST only |
| 1:00 AM | 11:30 AM | IST only |
| 2:00 AM | 12:30 PM | IST only |
| 3:00 AM | 1:30 PM | IST only |
| 4:00 AM | 2:30 PM | IST only |
| 5:00 AM | 3:30 PM | IST only |
| 6:00 AM | 4:30 PM | IST only |
| 7:00 AM | 5:30 PM | — |
| 8:00 AM | 6:30 PM | — |
| 9:00 AM | 7:30 PM | COT only |
| 10:00 AM | 8:30 PM | COT only |
| 11:00 AM | 9:30 PM | COT only |
| 12:00 PM | 10:30 PM | COT only |
| 1:00 PM | 11:30 PM | COT only |
| 2:00 PM | 12:30 AM next day | COT only |
| 3:00 PM | 1:30 AM next day | COT only |
| 4:00 PM | 2:30 AM next day | COT only |
| 5:00 PM | 3:30 AM next day | — |
| 6:00 PM | 4:30 AM next day | — |
| 7:00 PM | 5:30 AM next day | — |
| 8:00 PM | 6:30 AM next day | — |
| 9:00 PM | 7:30 AM next day | — |
| 10:00 PM | 8:30 AM next day | — |
| 11:00 PM | 9:30 AM next day | IST only |
What COT and IST Actually Are
COT — Colombia Time
Bogotá, Medellín, Cali, Barranquilla. Standing at UTC-5:00 as written, and the region does not change its clocks, so that offset holds all year.
Colombia briefly tried daylight saving during the energy crisis of 1992-93 and has not repeated it.
IST — India Standard Time
Mumbai, Delhi, Bengaluru, Chennai, Kolkata, Hyderabad — and Colombo. Standing at UTC+5:30 as written, and the region does not change its clocks, so that offset holds all year. IST also stands for Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2). This page covers the Indian one, which is by far the most searched.
India runs a single time zone across a country wide enough for two, which is why sunrise in the north-east can come nearly two hours before Mumbai's. Proposals for a second zone resurface regularly and have never been adopted.
What This Means in Practice
Expect times on the half hour
IST sits on a 30-minute offset rather than a whole hour, so a round number on one side is never a round number on the other. A 9:00 meeting becomes 30 minutes past the hour, which is exactly the detail calendar invitations get wrong when someone converts in their head.
The date changes mid-working-day
For 3 of the eight hours in a normal COT working day, the equivalent IST time falls on a different calendar date. Anything scheduled in that stretch needs the date checked as well as the time, or a Tuesday call quietly becomes a Wednesday one at the other end.
A gap you can rely on
Neither region changes its clocks, so this difference holds every day of the year. A recurring meeting booked once stays correct — worth knowing, because most cross-border pairs cannot say that.
Nearly opposite sides of the clock
At 10 hours and 30 minutes apart, one side's morning is the other side's night. Handing work over at the end of a shift usually beats trying to get both parties in the same call.
Major Cities in Each Zone
Cities on COT
Cities on IST
Frequently Asked Questions
What is the time difference between COT and IST?
IST is 10 hours and 30 minutes ahead of COT.
What is 9:00 AM COT in IST?
9:00 AM COT is 7:30 PM IST.
What are the best hours to schedule a call between COT and IST?
Standard business hours in these two zones do not overlap at all, so one side has to work outside the 9-to-5. The most workable window is 7:00 AM to 12:00 PM COT, which is 5:30 PM to 10:30 PM IST.
Does the difference between COT and IST change during the year?
No. Neither region changes its clocks, so this gap is fixed all year round.
Does IST always mean India Standard Time?
IST also stands for Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2). This page covers the Indian one, which is by far the most searched.