IST to JST Converter – Convert Indian Time to Japan Time
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Complete IST ↔ JST Conversion Table
All 24 hours · Both DST seasons · Best meeting windows marked ★
| IST Time | JST Time UTC+5:30 → UTC+9 (+3h 30m, constant) |
|---|---|
| 12:00 AM (midnight) | 3:30 AM |
| 1:00 AM | 4:30 AM |
| 2:00 AM | 5:30 AM |
| 3:00 AM | 6:30 AM |
| 4:00 AM | 7:30 AM |
| 5:00 AM | 8:30 AM |
| 6:00 AM | 9:30 AM |
| 7:00 AM | 10:30 AM |
| 8:00 AM | 11:30 AM |
| ★ 9:00 AM | ★ 12:30 PM |
| ★ 10:00 AM | ★ 1:30 PM |
| ★ 11:00 AM | ★ 2:30 PM |
| ★ 12:00 PM (noon) | ★ 3:30 PM |
| ★ 1:00 PM | ★ 4:30 PM |
| 2:00 PM | 5:30 PM |
| 3:00 PM | 6:30 PM |
| 4:00 PM | 7:30 PM |
| 5:00 PM | 8:30 PM |
| 6:00 PM | 9:30 PM |
| 7:00 PM | 10:30 PM |
| 8:00 PM | 11:30 PM |
| 9:00 PM | +1 12:30 AM |
| 10:00 PM | +1 1:30 AM |
| 11:00 PM | +1 2:30 AM |
What is the time difference between IST and JST?
JST is 3 hours 30 minutes ahead of IST. Neither IST nor JST observes Daylight Saving Time, so this gap never changes. 9:00 AM IST = 12:30 PM JST. 12:00 PM IST = 3:30 PM JST. 5:00 PM IST = 8:30 PM JST.
What is the best time to call from Mumbai to Tokyo?
The business hours overlap between IST and JST runs from 9:00 AM to 1:30 PM IST (12:30 PM to 5:00 PM JST). Scheduling calls in this window keeps both sides within normal working hours.
Frequently Asked Questions about IST and JST
JST is 3 hours 30 minutes ahead of IST, so to convert mentally, add 3 hours 30 minutes to your IST time. For example: 9:00 AM IST = 12:30 PM JST.
JST (Japan Standard Time, UTC+9) is 3 hours 30 minutes ahead of IST (India Standard Time, UTC+5:30) during standard time. For example, 9:00 AM IST = 12:30 PM JST.
The best overlap for standard business hours (9 AM–5 PM) in both zones is 09:00–13:30 IST = 12:30–17:00 JST. Schedule recurring calls in this window to keep both sides within normal working hours. Remember to re-check the window in March and November (or March/October for European zones) when DST transitions can shift the overlap by 1 hour.
India does not observe Daylight Saving Time. IST remains constant year-round, which simplifies conversions.
Major cities in the IST (India Standard Time, UTC+5:30) timezone include: Mumbai, New Delhi, Bangalore, Chennai, Kolkata, Hyderabad, Pune. IST is a fixed-offset zone - these cities do not observe Daylight Saving Time.
Major cities in the JST (Japan Standard Time, UTC+9) timezone include: Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Fukuoka. JST is a fixed-offset zone - these cities do not observe Daylight Saving Time.
JST is 3 hours 30 minutes ahead of IST. The best overlap for business hours is 09:00–13:30 IST = 12:30–17:00 JST. Always include both local times in calendar invites (for example, "2:00 PM IST / 5:30 PM JST JST"). Double-check around March and November (or March/October for European zones) when DST transitions can shift the offset by 1 hour. For full scheduling guidance, see our international meeting times guide.
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