IST to CDT Time Converter

Common Times Converted

IST on the left, CDT on the right.

IST to CDT: Full 24-Hour Conversion Table

Shaded rows are working hours; the darker shade marks the hours when both zones are at work.

What IST and CDT Actually Are

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.

CDT — Central Daylight Time

Chicago, Houston, Dallas, Winnipeg. Standing at UTC-5:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to CST. Mexico abolished daylight saving in 2022, so Mexico City stays on UTC-6 all year and no longer uses CDT.

Mexico left this pattern behind in 2022, abolishing daylight saving nationwide except in a strip of cities along the US border that kept it for cross-frontier trade.

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 2 of the eight hours in a normal IST working day, the equivalent CDT 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.

This gap is not fixed

CDT changes its clocks and IST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, November 1, 2026 unless someone resets it.

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 IST

Cities on CDT