Why India Has Only One Time Zone
India runs the whole country on one clock: Indian Standard Time, UTC+05:30. There's no daylight saving, so it doesn't change all year. India is a wide country, though, and that single clock suits the west a lot better than the east.
One zone, coast to coast
Someone in Gujarat and someone in Arunachal Pradesh see exactly the same time on their phones, even though the sun rises close to two hours earlier in the east. And because India never moves its clocks, whenever the gap between India and another country changes, it's the other country that moved. For the live time, open IST time now.
Where the odd 30 minutes comes from
Standard time is tied to a line of longitude, and India's is 82.5 degrees east, which passes near Vindhyachal in the Mirzapur district of Uttar Pradesh. Every 15 degrees is an hour, so 82.5 degrees works out to 5.5 hours ahead of UTC. The country's reference observatory sits at Shankargarh Fort, near Prayagraj, the nearest convenient spot to that line. India isn't alone here, by the way; several other places use half-hour and 45-minute time zones.
A clock that took 50 years to settle
Indian Standard Time came in on 1 January 1906. Before that the railways ran on Madras time and every big city kept its own local clock, and two of them didn't want to let go: Calcutta (Kolkata) held on to its own time until 1948 and Bombay (Mumbai) until 1955. The name "IST" was formally declared in 1947.
The long argument about a second zone
People have been debating this for decades, and it's not hard to see why. India stretches roughly 2,900 km from east to west, so in the north-east the sun is up very early and gone by late afternoon. Tea estates in Assam have long run an informal "Chaibagan" time, an hour ahead of IST, so work can start with the daylight.
Government committees looked at the idea in 2001 and again in 2004 and didn't recommend a change. Assam's chief minister pushed for a separate zone in 2014, and the Department of Science and Technology studied a two-zone plan in 2017. As of late 2026, nothing has changed, and India still has one zone.
No daylight saving, and why that matters to you
India doesn't use it at all. If you deal with India from a country that does change its clocks, the hour gap shifts twice a year, and that's what usually catches people out. The best time to call India from the USA and UK has a table for exactly this.
Writing an India time so nobody gets confused
Put "IST" or "UTC+05:30" next to the time and add the date. One catch: "IST" also stands for Irish Standard Time and Israel Standard Time, so adding the city or the offset removes any doubt. For conversions, the Time Zone Converter works for any date, or use the ready pages like IST to EST and IST to PST.
As for the neighbours, Sri Lanka also uses UTC+05:30, so its clocks match India's exactly, while Nepal at UTC+05:45 sits 15 minutes ahead.