IST to Ottawa Time Converter
Convert India Standard Time (IST) to Ottawa, Canada. Pick any date — daylight saving is applied from the IANA time zone database, so the answer is right in March and in November.
IST to Ottawa
IST is 9 hours and 30 minutes ahead of Ottawa.
Quick answer. Ottawa is 10 hours and 30 minutes behind IST for part of the year and 9 hours and 30 minutes behind for the rest, because Ottawa observes daylight saving time and the other side does not. The gap is 10 hours and 30 minutes during Ottawa's standard-time months and 9 hours and 30 minutes during daylight time, so always convert against a specific date.
Time difference
India Standard Time (IST)
IST UTC+5:30 No DST
Mumbai, Delhi, Bengaluru, Chennai, Kolkata, Hyderabad.
India runs on a single time zone, UTC+5:30, and has not observed daylight saving time since 1945. The half-hour offset is why IST conversions rarely land on a round hour.
Ottawa, Canada
EST UTC-5:00 EDT UTC-4:00 Observes DST
Ottawa and the rest of Canada.
- ↑ March 8, 2026 clocks forward at 3:00 AM · UTC-5:00 → UTC-4:00
- ↓ November 1, 2026 clocks back at 1:00 AM · UTC-4:00 → UTC-5:00
IST to Ottawa conversion table
Every hour of the day for 2026. Because Ottawa changes clocks twice a year, these values shift by an hour across the daylight saving boundary — use the date picker above for a specific day.
| IST | Ottawa | 24-hour |
|---|---|---|
| 12 AM | 2:30 PM −1 day | 14:30 |
| 1 AM | 3:30 PM −1 day | 15:30 |
| 2 AM | 4:30 PM −1 day | 16:30 |
| 3 AM | 5:30 PM −1 day | 17:30 |
| 4 AM | 6:30 PM −1 day | 18:30 |
| 5 AM | 7:30 PM −1 day | 19:30 |
| 6 AM | 8:30 PM −1 day | 20:30 |
| 7 AM | 9:30 PM −1 day | 21:30 |
| 8 AM | 10:30 PM −1 day | 22:30 |
| 9 AM | 11:30 PM −1 day | 23:30 |
| 10 AM | 12:30 AM | 00:30 |
| 11 AM | 1:30 AM | 01:30 |
| 12 PM | 2:30 AM | 02:30 |
| 1 PM | 3:30 AM | 03:30 |
| 2 PM | 4:30 AM | 04:30 |
| 3 PM | 5:30 AM | 05:30 |
| 4 PM | 6:30 AM | 06:30 |
| 5 PM | 7:30 AM | 07:30 |
| 6 PM | 8:30 AM | 08:30 |
| 7 PM | 9:30 AM | 09:30 |
| 8 PM | 10:30 AM | 10:30 |
| 9 PM | 11:30 AM | 11:30 |
| 10 PM | 12:30 PM | 12:30 |
| 11 PM | 1:30 PM | 13:30 |
No row is highlighted because a standard 9–6 day in IST never overlaps a 9–5 day in Ottawa — see the meeting section below for the closest workable slots.
Popular conversion times
| IST | Ottawa |
|---|---|
| 9 AM IST | 11:30 PM−1 day |
| 10 AM IST | 12:30 AM |
| 11 AM IST | 1:30 AM |
| 12 PM IST | 2:30 AM |
| 3 PM IST | 5:30 AM |
| 5 PM IST | 7:30 AM |
| 6 PM IST | 8:30 AM |
| 8 PM IST | 10:30 AM |
Business hours and meeting times
Comparing a 9:00–18:00 working day in IST against 9:00–17:00 in Ottawa, across the whole week — a slot only counts if it lands on a working day at both ends.
Both sides work Monday to Friday, so the working weeks line up and you share 5 days.
Rows are days in IST. Columns are hours of the IST day.
No standard overlap
A 9–6 day in IST never meets a 9–5 day in Ottawa on any day of the week, so one side has to move outside normal hours. Ranked by how far outside:
- 5 PM IST = 7:30 AM Ottawa — needs roughly 1 hour and 30 minutes of stretch
- 4 PM IST = 6:30 AM Ottawa — well outside normal hours — 2 hours and 30 minutes beyond
- 3 PM IST = 5:30 AM Ottawa — well outside normal hours — 3 hours and 30 minutes beyond
These hold on every shared working day (5 a week). Teams working this gap regularly tend to alternate which side takes the early or late call, and keep the synchronous meeting short.
Public holidays
A shared working day is only usable if neither side is on holiday — and India and Ottawa build their calendars on different systems, so the days each loses rarely coincide.
Over the next 8 weeks you share 40 working days. 4are lost to a public holiday on one side or the other, leaving 36.
| Date | Who is off | Holiday |
|---|---|---|
| Wednesday, September 30, 2026 | Ottawa | National Day for Truth and Reconciliation |
| Friday, October 2, 2026 | India | Gandhi Jayanti |
| Monday, October 12, 2026 | Ottawa | Thanksgiving |
| Tuesday, October 20, 2026 | India | Dussehra (Vijayadashami) |
Next holidays in India
- Friday, October 2, 2026Gandhi Jayantisame date every year
- Tuesday, October 20, 2026Dussehra (Vijayadashami)partialpublished date
- Sunday, November 8, 2026Diwalipublished date
- Monday, November 9, 2026Diwalipublished date
- Friday, December 25, 2026Christmas Daypartialsame date every year
India has three national holidays on which the whole country closes. Everything else is either a central-government gazetted holiday that individual employers choose to observe, or a state holiday. Festival dates follow lunisolar calendars and move every year, so they are listed explicitly rather than derived.
Next holidays in Ottawa
- Wednesday, September 30, 2026National Day for Truth and Reconciliationpublished date
- Monday, October 12, 2026Thanksgivingpublished date
- Wednesday, November 11, 2026Armistice Day / Remembrance Dayregionalpublished date
- Friday, December 25, 2026Christmas Daypublished date
- Saturday, December 26, 2026St. Stephen's Day (Boxing Day)regionalpublished date
Public holidays as published by https://date.nager.at, covering 2026–2028. Regional and employer-specific days are not included.
Holiday dates for Ottawa and elsewhere come from a dataset last refreshed on 2026-09-12 (date.nager.at plus curated national calendars). Lunar dates — Eid, Chinese New Year, the Jewish holidays — are predicted and can move by a day once officially announced. Regional, state and employer-specific holidays are not included. Confirm anything you are booking a flight around.
About this conversion
India runs on a single time zone, UTC+5:30, and has not observed daylight saving time since 1945. The half-hour offset is why IST conversions rarely land on a round hour.
Frequently asked questions
What is the time difference between IST and Ottawa?
It depends on the date. Ottawa is 10 hours and 30 minutes behind IST in January and 9 hours and 30 minutes behind in July, because Ottawa changes clocks for daylight saving time. Use the converter above with the date you actually need.
What time is 9 AM IST in Ottawa?
9:00 AM IST is 10:30 PM the previous day in Ottawa during EST, and 11:30 PM the previous day during EDT. The table on this page lists all 24 hours for the date you pick.
What is the best time for a meeting between IST and Ottawa?
Standard working days do not overlap at all in this pair, so somebody has to stretch. The closest slot is 5 PM IST / 7:30 AM Ottawa — it needs roughly 1 hour and 30 minutes of stretch. Teams that meet regularly across this gap usually alternate who takes the awkward end.
Does India observe daylight saving time?
No. India has kept a single UTC+5:30 offset since 1945 and does not use daylight saving time, so IST reads the same on every date of the year. Any change in the gap to Ottawa comes entirely from the other side.
When do the clocks change in Ottawa?
In 2026, clocks in Ottawa go forward on March 8, 2026 and back on November 1, 2026. Between those dates the gap from India is 9 hours and 30 minutes; outside them it is 10 hours and 30 minutes.
Why does the IST–Ottawa difference change during the year?
Because Ottawa switches between EST (UTC-5:00) and EDT (UTC-4:00) for daylight saving, while the other side does not move. A converter that assumes one fixed gap will be an hour wrong for roughly half the year.
How many hours a week do IST and Ottawa actually overlap?
None at standard hours. A 9–6 day in IST does not meet a 9–5 day in Ottawa on any day of the week, so a recurring call means one side works early or late — the section above ranks the least disruptive options.
Do public holidays in IST and Ottawa line up?
Barely. Over the next eight weeks the two sides share 40 working days, and 4 of those are a public holiday on one side or the other, leaving 36. The next holiday in Ottawa is National Day for Truth and Reconciliation on 2026-09-30. Indian, Gulf and Western holiday calendars are built on different systems, so the days each side loses rarely coincide.
Is IST ahead of Ottawa?
Yes. IST runs ahead of Ottawa — by 9 hours and 30 minutes or 10 hours and 30 minutes depending on the season, so a working morning in IST lands the previous evening or night in Ottawa.
Other cities in Canada
- IST to Toronto · Canada
- IST to Montreal · Canada
- IST to Vancouver · Canada
- IST to Calgary · Canada
Related converters
- IST to EST · Eastern Time
- IST to CST · Central Time
- IST to PST · Pacific Time
- IST to UTC · Coordinated Universal Time
- IST to GMT · Greenwich Mean Time
- IST to CET · Central European Time
- IST to GST · Gulf Standard Time
- IST to MST · Mountain Time
All cities in Canada: IST to Canada.