India Standard Time
India sits at UTC+5:30 and the clock never moves for daylight saving. The working day runs roughly 09:30 to 18:30 IST. Against the US, the shared window shrinks to one or two hours at the edges of both days. Against Europe, the shared window is comfortable. Against Asia-Pacific, it is straightforward. The cost of the awkward slot gets assigned to someone, and if you never decide who, it will always be the Indian team.
Core office hours in India
The typical Indian office day runs 09:30 to 18:30 IST, Monday through Friday. Government offices often start at 09:00 and close at 17:30. Many businesses pause for lunch roughly 13:00 to 14:00 IST. Do not schedule meetings during that hour.
IT and BPO sectors operate on shift patterns that cover global clients. The US shift typically runs 17:30 to 02:30 IST. The UK shift runs 13:00 to 22:00 IST. When you schedule with a team that works a specific shift, confirm their local start time. Do not assume the 09:30 opening.
US and India shared working hours
The size of the shared window determines how much flexibility you have.
US East Coast and India
On 15 January 2026, New York is 10.5 hours behind IST. On 15 July 2026, New York is 9.5 hours behind IST. The working window is narrow: 07:30 to 10:00 Eastern equals 18:00 to 20:30 IST. The Indian team takes a late-evening meeting, or the US team takes an early-morning one. Rotate the slot rather than assigning it permanently.
US West Coast and India
Los Angeles is 13.5 hours behind IST in January and 12.5 hours behind in July. The window is barely an hour. In winter, 08:00 to 09:00 Pacific equals 20:00 to 21:00 IST. In summer, 07:00 to 08:00 Pacific equals 19:30 to 20:30 IST.
UK and India
India is 5.5 hours ahead of GMT in winter and 4.5 hours ahead of British Summer Time in summer. The shared window is comfortable. In winter, 09:00 to 12:00 London equals 13:30 to 16:30 IST. In summer, the same London slot lands at 14:30 to 17:30 IST.
Continental Europe and India
Paris is 4.5 hours behind IST in winter and 3.5 hours behind in summer. Schedule 09:00 to 12:00 CET. That gives you 13:30 to 16:30 IST in winter and 12:30 to 15:30 IST in summer. Both sit inside the Indian working day.
Asia Pacific and India
Singapore is 2.5 hours ahead of IST. Tokyo is 3.5 hours ahead. Sydney is 5.5 hours ahead in January and 4.5 hours ahead in July. The shared window works well. Schedule 09:00 to 12:00 IST. That equals 11:30 to 14:30 SGT or 12:30 to 15:30 JST.
India in a follow-the-sun handoff
In a global workflow, India often sits in the middle shift. The pattern: Asia-Pacific works the morning, hands off to India in the afternoon, who then hands off to the Americas in the evening. This model works only if the handover is documented, not spoken. Write the status in the ticket. The next person picks it up without asking.
Time slots by region
| Region | Best IST Slot | Best Local Slot | Notes |
|---|---|---|---|
| US East Coast | 18:00 to 20:30 IST | 07:30 to 10:00 ET | Narrow; rotate |
| US West Coast | 19:30 to 21:00 IST | 07:00 to 08:30 PT | Very narrow |
| UK | 13:30 to 16:30 IST | 09:00 to 12:00 GMT | Comfortable |
| Europe (CET) | 13:30 to 16:30 IST | 09:00 to 12:00 CET | Comfortable |
| Gulf (Dubai) | 09:30 to 18:30 IST | 08:00 to 17:00 GST | Full shared window |
| Singapore | 09:00 to 12:00 IST | 11:30 to 14:30 SGT | Good shared window |
| Tokyo | 09:00 to 12:00 IST | 12:30 to 15:30 JST | Good shared window |
| Sydney | 09:00 to 12:00 IST | 14:30 to 17:30 AEST | Narrower |
Set up calendars without an IST mix-up
"Ist" is ambiguous. It can mean Indian Standard Time (UTC+5:30), Israel Standard Time (UTC+2:00), or Irish Standard Time (UTC+1:00). Scheduling software sometimes resolves it to the wrong zone.
Always write "India Standard Time" or "UTC+5:30" in calendar invites. Set your own calendar to the IANA zone Asia/Kolkata. Do not use "Asia/New_Delhi". That zone does not exist in the IANA database. For detailed setup instructions, see the India time zone settings page.
When you use a converter, check the output against a known reference. Some converters apply daylight saving to India incorrectly. Use the IST Converter to verify.
Cultural scheduling etiquette
Indian teams are often flexible about late meetings, especially in IT and BPO sectors where night shifts are normal. That flexibility can be exploited without noticing. A team that never asks who is taking the 22:00 call will find it is always the same people.
Three rules prevent this. First, cap the number of out-of-hours calls any individual takes per month. Second, rotate the expensive slot: alternate a 20:30 IST call with a 07:30 US East Coast call. Third, record meetings that run outside someone's working hours and provide a written summary.
When you invite, specify the time in both zones. "Meeting at 15:00 IST (09:30 GMT)" is clear. "Meeting at 15:00" without a zone is not.
Indian holidays and seasons that block the calendar
India has a dense holiday calendar, and many holidays shift date each year. These are public holidays in 2026:
- Republic Day: Monday 26 January
- Holi: Wednesday 4 March
- Eid al-Fitr: Saturday 21 March
- Ram Navami: Thursday 26 March
- Good Friday: Friday 3 April
- Dr. B. R. Ambedkar's Birthday: Tuesday 14 April
- Buddha Purnima: Friday 1 May
- Eid al-Adha: Wednesday 27 May
- Independence Day: Saturday 15 August
- Janmashtami (Vaishnava): Friday 4 September
- Mahatma Gandhi's Birthday: Friday 2 October
- Dussehra: Tuesday 20 October
- Diwali (Deepavali): Sunday 8 November
- Guru Nanak's Birthday: Tuesday 24 November
- Christmas: Friday 25 December
Diwali, Holi, and Dussehra are widely observed. Many people take extended leave around these dates.
Wedding season runs roughly November to February, especially in northern India. Expect leave requests during this period. Confirm availability at least two weeks in advance.
For a full list of business hours and holidays, see Indian Business Hours and Holidays.
Common scheduling mistakes
- Assuming Saturday is a weekend day. Government offices and banks are closed on Saturdays. Many private offices work half-days. Sunday is the near-universal weekly holiday.
- Scheduling during lunch. Block 13:00 to 14:00 IST.
- Using "IST" without clarification. Always write "India Standard Time" or "UTC+5:30".
- Assuming the Indian team works 9 to 5. Standard hours are 09:30 to 18:30.
- Forgetting the date roll. A meeting at 09:00 US East Coast is 18:30 IST on the same day. A meeting at 16:00 US East Coast is 02:30 IST the next day.
- Not confirming holiday availability. Indian holidays vary by state and religion. Check with the individual.
Sample schedule templates
Weekly standup: US East Coast and India Rotate between 08:00 ET (18:30 IST) one week and 07:30 ET (18:00 IST) the next. Cap duration at 30 minutes. Document decisions in a shared note.
Daily handover: India and UK Fix the slot at 15:00 IST (09:30 GMT in winter, 10:30 BST in summer). Cap duration at 15 minutes. The person going off shift writes a one-paragraph status update before the call.
Monthly all-hands: US, Europe, India Fix the slot at 14:00 CET (17:30 IST, 08:00 ET in winter, 07:00 ET in summer). Cap duration at one hour. Record the meeting. Provide a written summary within 24 hours.
For specific time difference calculations, use the India to USA Time or India to UK Time pages.