What the live IST clock above is showing you
India Standard Time. Fixed at UTC+5:30. The abbreviation IST is shared with Ireland and Israel, but the offset is not. For India, it is always five and a half hours ahead of Coordinated Universal Time. That single legal time covers the entire country. No other offset applies anywhere in India on any date.
The IANA time zone identifier is Asia/Kolkata. Every device in India, from the railway station master's clock to a smartphone in a tea garden in Assam, uses this one zone.
Why every clock in India reads the same number
India stretches roughly 29 degrees of longitude. That is nearly two full hours of solar span. The sun rises in the northeast while it is still dark in the west. Yet every clock in the country shows the same time.
The government chose a single time zone in 1906, based on the 82.5°E meridian passing through Mirzapur, Uttar Pradesh. After independence in 1947, the Republic of India kept the same offset. Proposals to split the country into two zones (an eastern zone at UTC+6:00, a western zone at UTC+5:30) have been discussed multiple times: a 2006 Planning Commission report, a 2018 CSIR-NPL proposal, a 2021 parliamentary question. None was adopted. India remains a one-zone country.
For the full story, read India One Time Zone Explained.
What time is it in Delhi, Mumbai, Bengaluru and Kolkata right now?
All four cities show the same clock. The table below lists their coordinates. Daylight figures are for New Delhi, the capital.
| City | IANA Zone | Offset | DST |
|---|---|---|---|
| New Delhi | Asia/Kolkata | UTC+5:30 | None |
| Mumbai | Asia/Kolkata | UTC+5:30 | None |
| Bengaluru | Asia/Kolkata | UTC+5:30 | None |
| Kolkata | Asia/Kolkata | UTC+5:30 | None |
New Delhi daylight extremes (2026): - June solstice (21 June): sunrise 05:23, sunset 19:21. 13 hours 58 minutes of daylight. - December solstice (21 December): sunrise 07:09, sunset 17:28. 10 hours 19 minutes of daylight.
The gap between the longest and shortest day in Delhi exceeds 3.5 hours. The clock does not adjust for it.
IST vs your local time: how to convert
The time differences shift when other countries change their clocks for summer. India never changes. That means the gap between IST and a DST-observing city grows or shrinks twice a year.
Example: New York vs New Delhi (IST) - 15 January 2026 (New York is on Eastern Standard Time, UTC-5): New York is 10.5 hours behind IST. When it is 10:00 in New York, it is 20:30 in Delhi. - 15 July 2026 (New York is on Eastern Daylight Time, UTC-4): New York is 9.5 hours behind IST. When it is 10:00 in New York, it is 19:30 in Delhi.
The difference shrinks by one hour in summer because New York springs forward. India does not.
Other key cities on 15 July 2026: - London: 4.5 hours behind IST - Dubai: 1.5 hours behind IST - Singapore: 2.5 hours ahead of IST - Tokyo: 3.5 hours ahead of IST - Sydney: 4.5 hours ahead of IST
For a full converter, see IST Time Zone Converters.
No summer time: the offset never changes in India
Daylight saving time has never been observed in independent India. The only exception was a brief wartime period from 1942 to 1945 under British rule. Since then, the offset has been constant.
The reasons are straightforward. India sits close to the equator. The difference between summer and winter day length is modest in the south (about one hour in Chennai) and only about 3.5 hours in the far north (Delhi). The energy savings from DST are small. The disruption to a large, complex country is high. No legislative change is pending for 2026 or 2027.
For more detail, see Does IST Use Daylight Saving Time?.
How a single time zone shapes daily life
The single zone creates a practical oddity. Offices in Guwahati open at 09:30 IST, but the sun has been up for hours. In the west, the evening stays light later.
Some Assam tea gardens unofficially operate on "Chaibagan Time" (UTC+6:30), one hour ahead of IST, to better match working hours to daylight. This is a local, non-statutory practice. See Chaibagan Time Assam.
Indian business hours in IST: - Government offices: 09:00-17:30 or 09:30-18:00, Monday, Friday. - Banks: 10:00-16:00 for public transactions. Second and fourth Saturdays are holidays. - Shops and markets: often 10:00-21:00, seven days a week in urban areas. - School hours: typically 07:30-14:00 or 08:00-14:30, Monday, Friday. Many have a half-day Saturday.
For more, see Indian Business Hours in IST.