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What Is IST?

One clock for 1.4 billion people, offset from UTC by an unusual half hour.

3 min read

India Standard Time (IST) is UTC+5:30 — the single timezone used across all of India, and also by Sri Lanka. It is one of the few half-hour offset zones in the world.

Why +5:30?

IST is based on the 82.5°E meridian near Mirzapur, chosen as a midpoint across India’s nearly 30° of longitude. That meridian sits exactly between the UTC+5 and UTC+6 lines — hence the half hour. The full story: Why is India 30 minutes off?

No Daylight Saving

India does not observe DST, so IST is fixed year-round. The gap to US and European cities changes twice a year anyway — because their clocks move. India is 10:30 ahead of New York in winter, 9:30 in summer.

Common IST Conversions

When it’s 12:00 PM ISTIt is
London6:30 AM (GMT) / 7:30 AM (BST)
New York1:30 AM (EST) / 2:30 AM (EDT)
Dubai10:30 AM
Singapore2:30 PM

Live clock and more on Time in India.

Time in India → EST to IST → Why +5:30? →

Frequently Asked Questions

What is IST in UTC?

IST is UTC+5:30 — five and a half hours ahead of Coordinated Universal Time, year-round.

Which countries use IST?

India and Sri Lanka both use UTC+5:30. (Note: IST can also abbreviate Irish Standard Time and Israel Standard Time in other contexts.)

Does IST change for daylight saving?

No. India does not observe daylight saving time, so IST is fixed at UTC+5:30 all year.