World Timezones

JST to IRST Converter

Compare IRST to JST instead
Japan Standard Time1:36 pmFri, Jun 5
Japan Standard TimeJST
Asia · UTC+9
1:36 pmFri, Jun 5
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
4p
5p
6p
7p
8p
9p
10p
11p
Iran Standard TimeIRST
Middle East · UTC+3:30
8:06 amFri, Jun 5
6p
7p
8p
9p
10p
11p
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
4p
5p

Offset

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

5.5 hours

Japan Standard Time (JST) is ahead of Iran Standard Time (IRST).

JST: UTC+9

IRST: UTC+3:30

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

When to schedule

Business-hours overlap: 3 PM–5 PM in Japan Standard Time (9 AM–11 AM in Iran Standard Time).

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

Suggested time: 4:00 PM Japan Standard Time (10:30 AM Iran 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

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

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

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

Quick reference

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

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

Daylight saving time

Neither Japan Standard Time nor Iran 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

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

Daylight overlap: 8h 35m — 10:20 AM–6:55 PM in Japan Standard Time (4:50 AM–1:25 PM in Iran 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 Japan Standard Time

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

Airports in Iran Standard Time

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

Related conversions

Common conversions

What is 9:00 am JST in IRST?
9:00 am JST is 3:30 am IRST.
What is 12:00 pm JST in IRST?
12:00 pm JST is 6:30 am IRST.
What is 12:30 pm JST in IRST?
12:30 pm JST is 7:00 am IRST.
What is 2:00 pm JST in IRST?
2:00 pm JST is 8:30 am IRST.
What is 5:00 pm JST in IRST?
5:00 pm JST is 11:30 am IRST.
What is 11:30 pm JST in IRST?
11:30 pm JST is 6:00 pm IRST.