Convert GST (Gulf Standard Time) to IST (India Standard Time)

Which IST is this?

IST names more than one zone. This page reads it as India Standard Time at UTC+5:30, which is the reading most converters take. There are others: Israel Standard Time at UTC+2, used in Israel in winter; Irish Standard Time at UTC+1, used in Ireland in summer.

The letters on a meeting invitation do not say which one is meant. If yours is not India Standard Time, the answer above is wrong, and not by a little:

Any converter has to pick one of these readings before it can answer, and two of them can pick differently — a page of search results for a IST conversion can show you both answers with neither being wrong. The one to trust is whichever states the zone it means rather than only the letters. Where it matters, ask which country the sender is in.

Best time to schedule a meeting

Standard 9–5 working hours overlap for 7 hours: 9:00 AM–4:00 PM GST (10:00 AM–5:00 PM IST). Schedule meetings inside that window.

GST to IST conversion table

About GST

Gulf Standard Time (GST) is UTC+4. It is used in Dubai, Abu Dhabi and Muscat.

Gulf Standard Time is UTC+4, covering the United Arab Emirates and Oman, and there is no daylight saving anywhere on the Arabian peninsula. The scheduling complication in the region is not the clock but the week: the UAE moved its weekend to Saturday–Sunday in 2022, while Saudi Arabia and several neighbours keep Friday–Saturday, so a Thursday afternoon meeting lands differently across a border that has no time difference at all.

About IST

India Standard Time (IST) is UTC+5:30. It is used in all of India and Sri Lanka, on a half-hour offset.

India Standard Time is UTC+5:30 — one of the handful of zones offset by half an hour, which breaks any code that assumes whole-hour offsets and any mental arithmetic that does the same. India has no daylight saving and one time zone for the entire country, despite spanning nearly 30 degrees of longitude. The abbreviation is also used for Irish Standard Time and Israel Standard Time, both of which are entirely different offsets.

Does this gap change with the seasons?

Neither GST nor IST shifts with the seasons, so this 1.5-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions