JST to Tehran Time Converter
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Quick answers
Selected conversion
9:00 pm21:00 JST (UTC+9), Oct 21, 2026 = 3:30 pm15:30 IRST (UTC+3:30), Oct 21, 2026
JST is 5 hours and 30 minutes ahead of Tehran.
How the time difference changes
JST is 5 hours and 30 minutes ahead of Tehran year-round.
Working hours of 9:00 am to 6:00 pm in JST correspond to 3:30 am to 12:30 pm in Tehran.Working hours of 09:00 to 18:00 in JST correspond to 03:30 to 12:30 in Tehran.
Compare JST time with Tehran time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Japan Standard Time is 5 hours and 30 minutes ahead of IRST (Iran Standard Time).
9:00 pm21:00 in JST is 3:30 pm15:30 in Tehran, Iran
JST to Tehran call time
Best time for a conference call or a meeting is between 2:30pm-6pm14:30-18:00 in JST which corresponds to 9am-12:30pm09:00-12:30 in Tehran
9:00 pm21:00 Japan Standard Time (JST). Offset UTC +9:00 hours
3:30 pm15:30 IRST (Iran Standard Time) (Tehran, Iran). Offset UTC +3:30 hours
9:00 pm21:00 JST / 3:30 pm15:30 Tehran, Iran
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Japan Standard Time
Offset: JST is 9 hours ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Japan
Principal Cities: The largest city in the JST time zone is Tokyo in Japan, with about 9.733 million people. Other major cities in this time zone include Yokohama, Osaka, Nagoya, Sapporo.
Daylight Saving: Clocks in Japan Standard Time (JST) do not change for daylight saving time, so JST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.
Current time in Japan: Japan time now
JST representations, usage and related time zones
- +09 - basic short
- +0900 - basic
- +09:00 - extended
- +0900 - sign character (+) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates an offset of nine hours to the east of the zero meridian.
- India - Military abbreviation for JST
- I - short form of 'India'
- Asia/Tokyo
- Japan
- AWDT - Australian Western Daylight Time
- CHOST - Choibalsan Summer Time
- I - India Time Zone
- IRKST - Irkutsk Summer Time
- JST - Japan Standard Time
- KST - Korea Standard Time
- PWT - Palau Time
- TLT - East Timor Time
- ULAST - Ulaanbaatar Summer Time
- WIT - Eastern Indonesian Time
- YAKT - Yakutsk Time