Field Notes · 7 MIN
US and UK time zone overlap with India teams: the real numbers
Exact working-hour overlap between India (IST) and the UK, US Eastern, and US Pacific, including the weeks when daylight saving dates do not line up.
India Standard Time (IST) is UTC+5:30 all year. That makes it 4.5 hours ahead of the UK in summer and 5.5 in winter, and 9.5 to 10.5 hours ahead of US Eastern and 12.5 to 13.5 ahead of US Pacific. A UK team overlaps with India for most of a working afternoon. US Eastern needs a late Indian shift, and US Pacific needs a split schedule.
- India does not observe daylight saving time, so the gap changes when your country changes its clocks.
- UK business hours overlap with a standard Indian day by 4.5 to 5.5 hours.
- US Eastern overlaps by half an hour or less with a standard Indian day (10 a.m. to 7 p.m. IST), and by 2.5 to 3.5 hours when the Indian team starts at 1 p.m.
- US Pacific works through a shared early-morning window on your side and an evening shift on the Indian side.
- The US and UK change clocks on different dates, so for a few weeks each year the usual gap is off by an hour.
- Nactore is an AI-native technology and growth company in Mumbai that sets the overlap window with each client at the start and writes it into the working agreement.
What is the time difference between India and the UK, US, and Pacific?
IST is fixed at UTC+5:30. The other sides move. The UK runs on Greenwich Mean Time in winter and British Summer Time in summer. The US runs on standard and daylight time. The table shows the gap for each.
| Your location | Season | Offset from UTC | India is ahead by |
|---|---|---|---|
| UK | Winter (GMT) | UTC+0 | 5.5 hours |
| UK | Summer (BST) | UTC+1 | 4.5 hours |
| US Eastern | Winter (EST) | UTC-5 | 10.5 hours |
| US Eastern | Summer (EDT) | UTC-4 | 9.5 hours |
| US Pacific | Winter (PST) | UTC-8 | 13.5 hours |
| US Pacific | Summer (PDT) | UTC-7 | 12.5 hours |
When it is 9:00 a.m. in London in winter, it is 2:30 p.m. in India. When it is 9:00 a.m. in New York in summer, it is 6:30 p.m. in India.
How many hours do business days actually overlap?
The overlap depends on the Indian team's schedule. This table assumes your day runs 9:00 a.m. to 6:00 p.m. local time (5:30 p.m. for the UK) and compares two Indian schedules. A standard day runs 10:00 a.m. to 7:00 p.m. IST. A late day runs 1:00 p.m. to 10:00 p.m. IST.
| Your location | Season | Overlap with standard Indian day | Overlap with late Indian day |
|---|---|---|---|
| UK | Winter | 4.5 hours | 7.5 hours |
| UK | Summer | 5.5 hours | 8.5 hours |
| US Eastern | Winter | 0 hours | 2.5 hours |
| US Eastern | Summer | 0.5 hours | 3.5 hours |
| US Pacific | Winter | 0 hours | 0 hours |
| US Pacific | Summer | 0 hours | 0.5 hours |
The numbers come from simple conversion. For example, US Eastern in winter starts at 9:00 a.m. EST, which is 7:30 p.m. IST, so a team that ends at 10:00 p.m. IST shares 2.5 hours with it.
How do UK companies handle the gap?
Easily, in most cases. A standard Indian day (10:00 a.m. to 7:00 p.m. IST) runs from 4:30 a.m. to 1:30 p.m. UK time in winter. Your working mornings are therefore shared, and daily calls fit anywhere between 9:00 a.m. and 1:30 p.m. Your afternoons are quiet on the Indian side, which suits review work. You read the day's handoff note, make decisions, and the team picks them up the next morning.
How do US East Coast companies handle the gap?
By shifting the Indian schedule. A team that works 1:00 p.m. to 10:00 p.m. IST shares your morning, which is 9:00 a.m. to 11:30 a.m. or 12:30 p.m. Eastern depending on the season. Those hours carry standups, reviews, and decisions. The rest of the Indian day is focused build time.
The pattern many US teams like is simple. You write the day's decisions before you leave, the Indian team builds in your pre-dawn hours, and an updated version is waiting when you start. See working across time zones for how handoffs are written.
How do US West Coast companies handle the gap?
Pacific is the hardest. A standard 9:00 a.m. Pacific start is 9:30 p.m. IST in summer and 10:30 p.m. in winter, so a live overlap requires either an evening-heavy Indian shift or an earlier start on your side. An 8:00 a.m. Pacific start is 8:30 p.m. IST in summer, which makes a one-hour meeting window workable.
For Pacific companies, plan for asynchronous work. Written briefs, recorded demos, and a shared task board carry most of the load, with one or two live sessions per week at a time you agree in advance.
Why is the gap different for a few weeks each year?
The US and UK do not change clocks on the same dates. The US Uniform Time Act, 15 U.S.C. 260a, sets US daylight saving time from the second Sunday of March to the first Sunday of November, though some places, such as Hawaii and most of Arizona, do not observe it, as the US Department of Transportation notes. GOV.UK states that UK clocks go forward on the last Sunday in March and back on the last Sunday in October.
That creates two mismatch windows each year.
| Year | US on summer time, UK still on winter time | UK back on winter time, US still on summer time |
|---|---|---|
| 2026 | 8 March to 28 March | 25 October to 31 October |
| 2027 | 14 March to 27 March | 31 October to 6 November |
During these weeks the UK to US Eastern gap is 4 hours instead of the usual 5. The India to UK gap stays at 5.5 hours, and the India to US Eastern gap is 9.5 hours. Meetings that sit in the same calendar slot week after week can move by an hour for no reason you can see, so check them in the weeks around the changes.
India itself does not change clocks, so the Indian side never moves.
What should you put in the working agreement?
Write down five things before the first sprint.
- The shared window. Start and end time in your time zone, with the season noted.
- The meeting rhythm. Which calls are live and which are written.
- Response times. What counts as urgent and how fast each side replies.
- The handoff note. One daily message listing what shipped, what is blocked, and what needs your decision.
- Holiday calendars. Indian public holidays and your own, shared a quarter ahead.
Put every recurring meeting in the calendar in UTC or in IST and let each person's calendar convert it. Anchoring to your local time is how the March and October mismatch weeks catch people out.
Frequently asked questions
What is the time difference between India and the UK?
India is 5.5 hours ahead of the UK in winter and 4.5 hours ahead in summer, because India stays on UTC+5:30 all year while the UK moves between GMT and BST.
Can a US company work live with an India team?
Yes, with a shifted schedule. East Coast companies get about 2.5 to 3.5 hours of live overlap with an Indian team that starts at 1:00 p.m. IST. West Coast companies rely more on written handoffs and a few live sessions.
Does India have daylight saving time?
No. IST is UTC+5:30 throughout the year, so the gap changes when the US or UK moves its clocks.
Is overlap more important than hours worked?
Overlap matters for decisions and review. Focus time matters for building. Plan for enough of the first to unblock the second.
Pick the overlap on purpose
The time gap is arithmetic, not a barrier. Decide the shared window, write the handoff habit, and mark the two weeks each year when the clocks disagree.
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