Time Zone Converter

Convert IST (Indian Standard Time) to any world time zone and back.

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Enter a date, time and select time zones above to convert

How time zone conversion works

Each time zone has a fixed offset from UTC (Coordinated Universal Time). To convert, we first convert the source time to UTC, then add the destination offset.

Conversion Formula
UTC = sourceTime − fromOffset
destTime = UTC + toOffset
Example: 10:00 IST (UTC+5:30) → UTC 04:30 → 00:30 EST (UTC−5)
Half-Hour Zones
IST = UTC+5:30, NPT = UTC+5:45
Several Asian time zones have non-whole-hour offsets. This tool handles all of them correctly.

IST and common conversions

IST to EST

IST (UTC+5:30) is 10 hours 30 minutes ahead of EST (UTC−5). A 9 AM IST meeting is 10:30 PM EST the previous evening.

IST to GMT

IST is 5 hours 30 minutes ahead of GMT/UTC. Noon IST is 06:30 GMT. The UK adds 1 hour during BST (summer).

IST to SGT

IST is 2 hours 30 minutes behind SGT (UTC+8). A 6 PM Singapore meeting falls at 3:30 PM in India.

Frequently asked questions

Does this account for Daylight Saving Time?

The tool uses fixed UTC offsets. Countries that observe DST (like the US, UK and most of Europe) shift their clocks seasonally. The offsets listed correspond to standard time. Select EDT instead of EST, or BST instead of GMT, when those countries are in summer time.

Why does India not observe Daylight Saving Time?

India adopted a single time zone (IST, UTC+5:30) in 1947 and has never observed DST. The country's east-west geographic spread is relatively narrow, and agricultural communities preferred stable sunrise/sunset patterns.

What is the difference between GMT and UTC?

For everyday purposes they are the same — both represent the world's primary time standard at 0° longitude. UTC is the scientific standard maintained by atomic clocks; GMT is the historical astronomical standard. The difference is less than 1 second.

Why are some time zones listed with half-hour offsets?

Countries like India (UTC+5:30), Nepal (UTC+5:45), Iran (UTC+3:30) and parts of Australia (UTC+9:30) use non-standard offsets for political or geographic reasons to better align sunrise/sunset with working hours.

What does "next day" or "previous day" mean in the result?

When the converted time crosses midnight, the date changes. "Next day" means the converted time falls on the calendar day after the input date; "previous day" means it falls the day before.