India Standard Time (ist) is used in India. The IANA timezone identifier is Asia/Kolkata.

Japan Standard Time (jst) is used in Japan. The IANA timezone identifier is Asia/Tokyo.

IST to JST Time Converter

India Standard Time → Japan Standard Time

IST = UTC+5:30JST = UTC+9

⚠️ IST is ambiguous — on this page it means India Standard Time. It also refers to:

Ireland Standard Time (Dublin) → JST ↗Israel Standard Time (Jerusalem) → JST ↗

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

JST (Tokyo)

Japan · +3.5h

12:30

London

United Kingdom · -4.5h

04:30

New York

USA · -9.5h

23:30-1 day

Dubai

United Arab Emirates · -1.5h

07:30

Sydney

Australia · +4.5h

13:30

IST (Mumbai) vs JST (Tokyo) — time difference

IST (Mumbai) is 4 hours 30 minutes behind JST (Tokyo). At noon in IST (Mumbai), your contact in JST (Tokyo) sees 15:00.

IST (Mumbai) runs on Asia/Kolkata; JST (Tokyo) runs on Asia/Tokyo. Together they are 3.5 hours 30 minutes apart.

Shared working hours

IST (Mumbai) and JST (Tokyo) share 4.5 hours of overlapping business hours daily — enough for real-time collaboration without anyone joining at odd hours.

00:0006:0012:0018:0024:00

IST (Mumbai)

JST (Tokyo)

Overlap (4.5h)

Best call times between these locations

There is a 4.5-hour daily window where both locations are in business hours. The 3 best slots are listed below.

09:00 Mumbai / 12:00 Tokyo✓ Both working

10:00 Mumbai / 13:00 Tokyo✓ Both working

11:00 Mumbai / 14:00 Tokyo✓ Both working

Working hours defined as 09:00–17:00 local time for each location.

Public holidays for both locations

IST (Mumbai)

No upcoming public holidays this year.

JST (Tokyo)7 holidays

Jul 20Marine Day

Aug 11Mountain Day

Sep 21Respect for the Aged Day

Sep 23Autumnal Equinox Day

Oct 12Sports Day

Scheduling between IST (Mumbai) and JST (Tokyo)

IST (Mumbai) (India) and JST (Tokyo) (Japan) are 3.5 hours apart. With a 4.5-hour daily overlap in standard business hours, both teams can connect in real time without either side stretching beyond their normal workday.

💡 Scheduling tips for these locations

✅

If you are in IST (Mumbai), aim for 09:00–10:00, which corresponds to 12:00–13:00 in JST (Tokyo) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 10:00–11:00, which corresponds to 13:00–14:00 in JST (Tokyo) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 11:00–12:00, which corresponds to 14:00–15:00 in JST (Tokyo) — both teams are within working hours.

Avoid scheduling mistakes — especially around daylight saving changes. Use the ClockinSync Chrome Extension to instantly verify and compare both time zones directly in your browser, without manual calculations.

Add to your browser — Free →

Need a specific time? Use the slider or type directly into the input bar — it understands "3pm", "15:30", and location-specific formats like "9am IST (Mumbai)".

IST (Mumbai) ↔ JST (Tokyo)

5h of business hours overlap daily (09:00–17:00)

IST (Mumbai)

JST (Tokyo)

00:00

03:30

01:00

04:30

02:00

05:30

03:00

06:30

04:00

07:30

05:00

08:30

06:00

09:30Working

07:00

10:30Working

08:00

11:30Working

09:00Working

12:30Working

10:00Working

13:30Working

11:00Working

14:30Working

12:00Working

15:30Working

13:00Working

16:30Working

14:00Working

17:30off

15:00Working

18:30off

16:00Working

19:30off

17:00

20:30

18:00

21:30

19:00

22:30

20:00

23:30

21:00

00:30+1d

22:00

01:30+1d

23:00

02:30+1d

Working hours: 09:00–17:00 local. Green = both working. Purple = one side only.

Frequently Asked Questions

What is the difference between ist and jst?

India Standard Time (ist) is UTC+5:30 and Japan Standard Time (jst) is UTC+9. The difference between them is 3.5 hours.

Where is ist used?

India Standard Time (ist) is used in India and surrounding regions. The IANA timezone identifier is Asia/Kolkata. Note: ist is ambiguous and may refer to other timezones.

Where is jst used?

Japan Standard Time (jst) is used in Japan and surrounding regions. The IANA timezone identifier is Asia/Tokyo.

How do I convert ist to jst?

Use the interactive converter above. Drag the time slider to any ist time and the jst equivalent updates instantly. You can also type a time like "3pm" or "15:00" in the input bar.

Popular IST conversions

IST → London IST → New York IST → Tokyo IST → Dubai IST → Sydney IST → Paris IST → Berlin IST → Singapore IST → Los Angeles IST → Toronto

Popular JST conversions

London → JST New York → JST Dubai → JST Sydney → JST Paris → JST Berlin → JST Singapore → JST Los Angeles → JST Toronto → JST Mumbai → JST