ISTtoJSTIndia Standard Time to Japan Standard Time
IST
India Standard Time (GMT+5:30)JST
Japan Standard Time (GMT+9)Mutual Working Window: 5 Overlapping Hours
Recommended calling window between IST and JST
Both locations share 5 overlapping standard business hours (9:00 AM – 5:00 PM). This is the premier window for real-time video conferences, corporate calls, and instant collaboration without outside-hours disruption.
24-Hour Schedule Conversion Matrix
Compare every hour of the day between IST and JST.
| IST Time (India Standard Time) | JST Time (Japan Standard Time) | Status & Recommendation |
|---|---|---|
| 00:00AM | 03:00AM | ⚪ Outside Work Hours |
| 01:00AM | 04:00AM | ⚪ Outside Work Hours |
| 02:00AM | 05:00AM | ⚪ Outside Work Hours |
| 03:00AM | 06:00AM | ⚪ Outside Work Hours |
| 04:00AM | 07:00AM | ⚪ Outside Work Hours |
| 05:00AM | 08:00AM | ⚪ Outside Work Hours |
| 06:00AM | 09:00AM | ⚪ Outside Work Hours |
| 07:00AM | 10:00AM | ⚪ Outside Work Hours |
| 08:00AM | 11:00AM | ⚪ Outside Work Hours |
| 09:00AM | 12:00PM | 🟢 Ideal Meeting Window |
| 10:00AM | 13:00PM | 🟢 Ideal Meeting Window |
| 11:00AM | 14:00PM | 🟢 Ideal Meeting Window |
| 12:00PM | 15:00PM | 🟢 Ideal Meeting Window |
| 13:00PM | 16:00PM | 🟢 Ideal Meeting Window |
| 14:00PM | 17:00PM | 🟡 Feasible (Shoulder Hour) |
| 15:00PM | 18:00PM | 🟡 Feasible (Shoulder Hour) |
| 16:00PM | 19:00PM | 🟡 Feasible (Shoulder Hour) |
| 17:00PM | 20:00PM | ⚪ Outside Work Hours |
| 18:00PM | 21:00PM | ⚪ Outside Work Hours |
| 19:00PM | 22:00PM | ⚪ Outside Work Hours |
| 20:00PM | 23:00PM | ⚪ Outside Work Hours |
| 21:00PM | 00:00AM | ⚪ Outside Work Hours |
| 22:00PM | 01:00AM | ⚪ Outside Work Hours |
| 23:00PM | 02:00AM | ⚪ Outside Work Hours |
Frequently Asked Questions
What is the time difference between IST and JST?
JST is 3 hours 30 minutes ahead of IST. When it is 12:00 PM (noon) in IST, the current synchronized time in JST is 3:30 PM.
What are the overlapping working hours between IST and JST?
There are 5 overlapping standard business hours (9:00 AM – 5:00 PM) between IST and JST. The optimal scheduling window is 9:00 AM – 2:00 PM in IST (12:00 PM – 5:00 PM in JST).
Does daylight saving time affect the conversion between IST and JST?
No. Neither IST nor JST observes daylight saving time; the offset difference remains constant throughout the year.
What regions and major cities observe IST and JST?
IST (India Standard Time) is primarily observed across South Asia (Republic of India & Sri Lanka) (key hubs include New Delhi, Mumbai, Bengaluru, Hyderabad). JST (Japan Standard Time) is observed across East Asia (Japan) (key hubs include Tokyo, Osaka, Yokohama, Nagoya).
What is 9:00 AM IST in JST?
9:00 AM in IST corresponds to 12:30 PM in JST. You can cross-reference every hour of the day in the 24-hour visual schedule table above.
Which time zone is ahead, IST or JST?
JST is ahead by 3 hours and 30 minutes.