What is the time difference between Tokyo and Tehran?

Tokyo (JST, UTC+9) is 5 hours 30 minutes ahead of Tehran in winter (IRST, UTC+3:30) and 4 hours 30 minutes ahead in summer (IRDT, UTC+4:30). Japan does not observe Daylight Saving Time, so the offset changes only when Iran shifts its clocks.

Does Tokyo observe Daylight Saving Time?

No. Japan abolished DST in 1952 and has not used it since. Tokyo stays on JST (UTC+9) all year. Only Tehran shifts its clocks, which is why the Tokyo-Tehran gap changes with Iranian DST.

When does Iran switch between IRST and IRDT?

Iran moves clocks forward by one hour at the start of Farvardin (around March 21 on the Gregorian calendar) and reverts at the end of Shahrivar (around September 22). This gives Iran a summer offset of UTC+4:30 (IRDT).

What are the best meeting times when calling from Tokyo to Tehran?

The overlap between standard business hours (09:00–18:00) exists in the early Tokyo morning. Tokyo at 12:30–18:00 JST corresponds roughly to Tehran at 08:00–13:30 IRST — that window covers the Tehran morning workday.

Is this tool accurate for scheduling?

Yes. It uses the IANA timezone database embedded in your browser — the same source used by operating systems and calendar apps worldwide. Accuracy depends on your device clock being synchronized via NTP, which most devices do automatically.

What is IRST and IRDT?

IRST stands for Iran Standard Time (UTC+3:30), used in winter. IRDT stands for Iran Daylight Time (UTC+4:30), used in summer. Iran is one of the few countries that uses a half-hour UTC offset.

Time Difference: Tokyo to Tehran

Name: Time Difference: Tokyo to Tehran
Availability: InStock
Author: Nham Vu

See the current time in Tokyo and Tehran side by side, with the live UTC offset — Tokyo is UTC+9 year-round; Tehran uses UTC+3:30 in winter and UTC+4:30 in summer.

Tokyo, Japan

--:--:--

JST UTC+9

Tehran, Iran

--:--:--

IRST UTC+3:30

Current Offset

+5h 30m

Tokyo is 5 hours 30 minutes ahead of Tehran

Convert Tokyo Time to Tehran Time

Based on the current offset — updates automatically

Tokyo (JST)	Tehran (IRST/IRDT)

Meeting Overlap Finder

Business hours (09:00–18:00) highlighted — best overlap shaded

Tokyo (JST)	Tehran (IRST/IRDT)	Status

Summary

See the current time in Tokyo and Tehran side by side, with the live UTC offset — Tokyo is UTC+9 year-round; Tehran uses UTC+3:30 in winter and UTC+4:30 in summer.

How it works

Your browser reads the current moment from your device clock.
It converts that moment to Asia/Tokyo time (JST, UTC+9) using the IANA timezone database built into modern browsers.
The same moment is converted to Asia/Tehran time (IRST UTC+3:30 in winter, IRDT UTC+4:30 in summer).
The UTC offsets of both cities are compared to calculate the exact hour and minute difference.
All three values — Tokyo time, Tehran time, and the offset — refresh every second.
When Iran switches between IRST and IRDT, the displayed offset adjusts automatically.

Use cases

Scheduling video calls between Tokyo and Tehran offices.
Checking if a colleague in Tehran is still at their desk.
Planning Japan-Iran travel and arrival time comparisons.
Remote teams coordinating daily standups across Japan and Iran.
Finding overlapping business hours for Tokyo-Tehran meetings.
Converting a Tokyo meeting time to its Tehran equivalent.
Journalists in Tokyo checking broadcast times for live Iran events.
Students and teachers arranging online lessons between Japan and Iran.

Frequently Asked Questions

Last updated: 2026-07-26 · Reviewed by Nham Vu