IST to World Cities: Quick Time Difference Reference Table

New York is 10.5 hours behind New Delhi in January and 9.5 hours behind in July. The gap shrinks by one hour because New York moves its clocks. India Standard Time (IST, UTC+5:30) stays put. Every other shift in the tables below follows the same rule: the other city changes, India does not.

IST vs US cities: New York, Chicago, Los Angeles

New York, Chicago and Los Angeles all observe daylight saving time. When they spring forward, the gap to IST narrows by one hour.

City	Offset from IST (January 2026)	Offset from IST (July 2026)
New York	10.5 hours behind	9.5 hours behind
Chicago	11.5 hours behind	10.5 hours behind
Los Angeles	13.5 hours behind	12.5 hours behind

What this means for calls. The standard overlap window for IT/BPO shifts with the US East Coast is 20:00-05:00 IST. That is 09:30-16:30 in New York in January and 10:30-17:30 in July. Need a morning meeting in New York? Your team in India works the evening before.

IST vs New York time | IST vs Chicago time | IST vs Los Angeles time

IST vs UK and Europe: London, Paris

The UK and most of Europe switch to summer time. London moves from GMT (UTC+0) to BST (UTC+1). Paris moves from CET (UTC+1) to CEST (UTC+2).

City	Offset from IST (January 2026)	Offset from IST (July 2026)
London	5.5 hours behind	4.5 hours behind
Paris	4.5 hours behind	3.5 hours behind

What this means for calls. The standard overlap window for IT/BPO shifts with the UK is 17:30-02:30 IST. That is 12:00-21:00 in London in January and 13:00-22:00 in July. Paris is one hour ahead of London in both seasons.

IST vs London time | IST vs Paris time

IST vs Asia Pacific: Tokyo, Singapore, Sydney

Tokyo and Singapore do not observe daylight saving time. Sydney does. It uses Australian Eastern Daylight Time (AEDT, UTC+11) in summer and Australian Eastern Standard Time (AEST, UTC+10) in winter.

City	Offset from IST (January 2026)	Offset from IST (July 2026)
Tokyo	3.5 hours ahead	3.5 hours ahead
Singapore	2.5 hours ahead	2.5 hours ahead
Sydney	5.5 hours ahead	4.5 hours ahead

What this means for calls. When Sydney is on AEDT (January), a 09:00 meeting in Sydney is 03:30 IST. On AEST (July), the same meeting is 04:30 IST. Tokyo and Singapore are constant. Plan around IST morning for Japan overlap (05:30-07:30 IST) or IST afternoon for Singapore (10:30-12:30 IST).

IST vs Tokyo time | IST vs Singapore time | IST vs Sydney time

IST vs Middle East: Dubai

Dubai does not observe DST. Its offset from IST never changes.

City	Offset from IST (all year)
Dubai	1.5 hours behind

A 10:00 meeting in Dubai is 11:30 IST. No seasonal adjustment needed.

IST vs Dubai time

IST vs Africa: Johannesburg

South Africa does not observe DST.

City	Offset from IST (all year)
Johannesburg	3.5 hours behind

IST vs Johannesburg time

How DST in other countries affects the difference

IST is fixed at UTC+5:30. The offset never changes.

Every time difference shift in the tables above is caused by a country that moves its clocks. The US, UK, and most of Europe move forward in spring and back in autumn. Australia's east coast does the same, but in opposite months.

The dates matter. In 2026, the US moves to daylight time on 8 March and back to standard time on1 November. The UK and Europe move on28 March and25 October. Sydney moves on4 April and3 October. Between those dates, the offsets in the "July" column apply. Outside them, the "January" column applies.

Frequently asked questions

Does India ever change its clocks?

No. India Standard Time is UTC+5:30 year-round. No DST, no seasonal shift, no proposal enacted.

Why is the India-New York difference 10.5 hours in winter but 9.5 hours in summer?

New York observes daylight saving time. In winter (EST, UTC-5) it is 10.5 hours behind IST. In summer (EDT, UTC-4) it is 9.5 hours behind. IST never changes, so the gap shrinks by one hour when New York springs forward.

What is the best overlap for a call between India and the UK?

For a working-hour overlap, schedule between 14:30 and 17:30 IST, which is 09:00-12:00 in London (GMT) or 10:00-13:00 in London (BST). IT/BPO shifts commonly run 17:30-02:30 IST to cover the UK afternoon and evening.

Is the time difference between India and Dubai constant?

Yes. Dubai uses Gulf Standard Time (UTC+4) year-round. Dubai is always 1.5 hours behind IST.

Why is Sydney 5.5 hours ahead of IST in January but 4.5 hours in July?

Sydney uses AEDT (UTC+11) in its summer (January) and AEST (UTC+10) in its winter (July). IST is UTC+5:30. The difference changes because Sydney shifts, not India.

Who should ignore the "standard overlap windows" above?

Anyone coordinating with a team in a city that does not observe DST, Dubai, Singapore, Tokyo, Johannesburg, should use the constant offset. The overlap windows in the first two sections are only relevant for US, UK, and European partners. For DST-free cities, pick any mutually convenient hour and reuse it every day of the year.