IST Stays on UTC+5:30 Every Day of the Year
A clock in New Delhi shows the same offset on 21 June as on 21 December: UTC+5:30. The country’s single time zone, Asia/Kolkata, does not shift. In 2026 and 2027, the offset will not change.
New Delhi sunrise on the June solstice is 05:23 IST, sunset 19:21 IST. That is 13 hours 58 minutes of daylight. On the December solstice, sunrise is 07:09 IST, sunset 17:28 IST, just 10 hours 19 minutes of daylight. The 3-hour 39-minute swing is absorbed entirely by the fixed offset. No clock moves forward or back.
Did India Ever Use DST During the War?
Yes, once. Under British rule, from 1942 to 1945, clocks advanced by one hour to UTC+6:30. The wartime order was a fuel-saving measure. It lapsed when the war ended. Independent India never reinstated it.
No DST law has passed through the Parliament of India. Every proposal since 1947 has been rejected or shelved. The 1942-1945 period remains the only time the subcontinent used a DST-like shift.
Why a Tropical Longitude Makes DST a Hard Sell
India spans roughly 29° of longitude. The sun rises and sets nearly two hours later in Gujarat than in Arunachal Pradesh. The country already absorbs that gap inside a single zone. Adding a seasonal shift would push the eastern sunrise even later, for marginal gain.
The energy arithmetic works against it. New Delhi’s daylight ranges from 10 hours 19 minutes in winter to 13 hours 58 minutes in summer. That is narrow compared to higher-latitude cities where DST actually shifts usable light. India’s Ministry of Power has reviewed the question multiple times. Each review concluded that the cost of resetting clocks, rescheduling transport, and confusing a population of over 1.35 billion outweighed any energy saving.
How DST Abroad Shifts the IST Gap
IST does not move. Every time a DST-observing country changes its clocks, the difference from IST shifts. That is the single fact to internalise.
On 15 January 2026, New York is 10.5 hours behind IST. On 15 July 2026, after the US moves to daylight time, New York is 9.5 hours behind. The gap shrinks by one hour. London goes from 5.5 hours behind in January to 4.5 behind in July. Paris drops from 4.5 behind to 3.5. Los Angeles from 13.5 behind to 12.5.
Cities without DST stay fixed. Dubai is always 1.5 hours behind IST. Singapore is always 2.5 hours ahead. Johannesburg is always 3.5 hours behind.
Sydney reverses the pattern. On 15 January, Australian summer, Sydney is 5.5 hours ahead. On 15 July, Australian winter with no DST, Sydney is 4.5 hours ahead. The gap narrows when Sydney falls back.
Rule of thumb: A country entering DST shrinks its IST gap by one hour. Exiting DST widens it by one hour. You track only one moving side.
A Second Time Zone Instead of DST
India has never pursued DST seriously, but splitting the country into two standard zones has been debated for decades. A second zone would set the northeastern states permanently at UTC+6:00, one hour ahead of IST, instead of shifting clocks seasonally.
Proposals came from the Planning Commission in 2006, the CSIR-National Physical Laboratory in 2018, and a parliamentary question in 2021. None were adopted. The arguments against include recalibrating railway timetables, confusion at state borders, and losing a single national reference. The debate is covered in full at India Two Time Zones Proposal: IST-I for the Northeast Explained.
Some Assam tea gardens use an informal "Chaibagan Time" of UTC+6:30, one hour ahead of IST. Workers follow it to use early daylight. It has no legal standing. See Chaibagan Time Assam: The Tea Garden Time One Hour Ahead of IST.