IST to GST

About India Standard Time

India keeps one clock, UTC+5:30, across a country spanning about 29 degrees of longitude — the sun rises nearly two hours earlier in Arunachal Pradesh than in Gujarat on the same clock. The half-hour offset means most conversions from India land on the half hour rather than the hour. Sri Lanka keeps the same time.

Cities on this clock: Mumbai, Delhi, Bangalore, Hyderabad, Chennai, Kolkata, Pune, Ahmedabad.

Watch out: IST is also Israel Standard Time (UTC+2) and Irish Standard Time (UTC+1). This page is the Indian one.

About Gulf Standard Time

The Gulf runs at a fixed UTC+4, with no clock changes. The half-hour offsets of South Asia start immediately to its east, so the step from Dubai to Karachi is one hour but the step from Dubai to Mumbai is an hour and a half.

Cities on this clock: Dubai, Abu Dhabi, Baku, Tbilisi.

How the difference is worked out

Neither India Standard Time nor Gulf Standard Time moves its clock relative to the other, so gulf standard time is 1 hour 30 minutes behind india standard time is a rule rather than a fact about one particular year. The hour-by-hour table above holds on every date.

With both zones on their own standard time — daylight saving not in force anywhere — Gulf Standard Time is 1 hour 30 minutes behind India Standard Time. That figure never changes; everything else on this page follows from it plus whichever clocks have moved.

Every figure here comes from the IANA time zone database via your browser's own Intl engine, using the zone ids Asia/Kolkata and Asia/Dubai. Nothing is looked up on a server and nothing about your visit is recorded.