World Timezones

IRST to JST Converter

Compare JST to IRST instead
Iran Standard Time8:06 amFri, Jun 5
Iran Standard TimeIRST
Middle East · UTC+3:30
8:06 amFri, Jun 5
12a
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12p
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11p
Japan Standard TimeJST
Asia · UTC+9
1:36 pmFri, Jun 5
5a
6a
7a
8a
9a
10a
11a
12p
1p
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Offset

The time difference between Iran Standard Time and Japan Standard Time is 5.5 hours.

5.5 hours

Iran Standard Time (IRST) is behind Japan Standard Time (JST).

IRST: UTC+3:30

JST: UTC+9

Neither Iran Standard Time nor Japan Standard Time is currently observing daylight saving time.

When to schedule

Business-hours overlap: 9 AM–12 PM in Iran Standard Time (2 PM–5 PM in Japan Standard Time).

Both teams are in working hours during this window on weekdays.

Suggested time: 10:00 AM Iran Standard Time (3:30 PM Japan Standard Time).

Public holidays in 2026

National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.

Japan

  • New Year's DayThu, Jan 1
  • Coming of Age DayMon, Jan 12
  • Foundation DayWed, Feb 11
  • The Emperor's BirthdayMon, Feb 23
  • Vernal Equinox DayFri, Mar 20
  • Shōwa DayWed, Apr 29
  • Constitution Memorial DayWed, May 6
  • Greenery DayMon, May 4
  • Children's DayTue, May 5
  • Marine DayMon, Jul 20
  • Mountain DayTue, Aug 11
  • Respect for the Aged DayMon, Sep 21
  • Autumnal Equinox DayWed, Sep 23
  • Sports DayMon, Oct 12
  • Culture DayTue, Nov 3
  • Labour Thanksgiving DayMon, Nov 23

About these zones

Iran Standard Time is also known as IRST. To call Iran, dial +98.

Japan Standard Time is also known as JST. To call Japan, dial +81.

Japan Standard Time is approximately 4,750 miles northeast of Iran Standard Time.

Quick reference

Full 24-hour conversion table — tap any time to open it in the converter.

IRSTJSTDay
12:00 am5:30 amSame day
1:00 am6:30 amSame day
2:00 am7:30 amSame day
3:00 am8:30 amSame day
4:00 am9:30 amSame day
5:00 am10:30 amSame day
6:00 am11:30 amSame day
7:00 am12:30 pmSame day
8:00 am1:30 pmSame day
9:00 am2:30 pmSame day
10:00 am3:30 pmSame day
11:00 am4:30 pmSame day
12:00 pm5:30 pmSame day
1:00 pm6:30 pmSame day
2:00 pm7:30 pmSame day
3:00 pm8:30 pmSame day
4:00 pm9:30 pmSame day
5:00 pm10:30 pmSame day
6:00 pm11:30 pmSame day
7:00 pm12:30 am+1 day
8:00 pm1:30 am+1 day
9:00 pm2:30 am+1 day
10:00 pm3:30 am+1 day
11:00 pm4:30 am+1 day

Daylight saving time

Neither Iran Standard Time nor Japan Standard Time observes daylight saving time. The offset between these zones remains constant year-round.

See the daylight saving time page for transition dates across every time zone.

Daylight today

Iran Standard Time
Sunrise
4:50 AM
Sunset
7:18 PM
Day length
14h 28m
Japan Standard Time
Sunrise
4:27 AM
Sunset
6:55 PM
Day length
14h 28m

Daylight overlap: 8h 35m — 4:50 AM–1:25 PM in Iran Standard Time (10:20 AM–6:55 PM in Japan Standard Time). Both locations are in daylight during this window.

Cities in these zones

Cities in Iran Standard Time

Browse all cities to see the current local time anywhere.

Airports in these zones

Airports in Iran Standard Time

  • IKA
  • THR
  • MHD
  • IFN
  • PYK
  • TBZ

Airports in Japan Standard Time

  • HND
  • NRT
  • ITM
  • KIX
  • UKB
  • NGO
  • NKM
  • CTS
  • OKD
  • FUK

Related conversions

Common conversions

What is 9:00 am IRST in JST?
9:00 am IRST is 2:30 pm JST.
What is 12:00 pm IRST in JST?
12:00 pm IRST is 5:30 pm JST.
What is 12:30 pm IRST in JST?
12:30 pm IRST is 6:00 pm JST.
What is 2:00 pm IRST in JST?
2:00 pm IRST is 7:30 pm JST.
What is 5:00 pm IRST in JST?
5:00 pm IRST is 10:30 pm JST.
What is 11:30 pm IRST in JST?
11:30 pm IRST is 5:00 am JST, the next day.