Updating current time…
RET
Reunion Time
GMT +4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
IRST
Iran Standard Time
GMT +3:30
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

4:00 pm16:00 RET (UTC+4), Oct 3, 2026 = 3:30 pm15:30 IRST (UTC+3:30), Oct 3, 2026

RET is 30 minutes ahead of IRST.

RET and IRST examples

These examples always use RET (UTC+4) and IRST (UTC+3:30). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

RET is 30 minutes ahead of IRST.

How the time difference changes

RET is 30 minutes ahead of IRST year-round.

Working hours of 9:00 am to 5:00 pm in RET correspond to 8:30 am to 4:30 pm in IRST.Working hours of 09:00 to 17:00 in RET correspond to 08:30 to 16:30 in IRST.

Compare RET time with IRST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Reunion Time is 30 minutes ahead of Iran Standard Time.
4:00 pm16:00 in RET is 3:30 pm15:30 in IRST

RET to IRST call time
Best time for a conference call or a meeting is between 9:30am-5pm09:30-17:00 in RET which corresponds to 9am-4:30pm09:00-16:30 in IRST

4:00 pm16:00 Reunion Time (RET). Offset UTC +4:00 hours
3:30 pm15:30 Iran Standard Time (IRST). Offset UTC +3:30 hours

4:00 pm16:00 RET / 3:30 pm15:30 IRST

RETIRST
12:00am11:30pm
1:00am12:30am
2:00am1:30am
3:00am2:30am
4:00am3:30am
5:00am4:30am
6:00am5:30am
7:00am6:30am
8:00am7:30am
9:00am8:30am
10:00am9:30am
11:00am10:30am
12:00pm11:30am
1:00pm12:30pm
2:00pm1:30pm
3:00pm2:30pm
4:00pm3:30pm
5:00pm4:30pm
6:00pm5:30pm
7:00pm6:30pm
8:00pm7:30pm
9:00pm8:30pm
10:00pm9:30pm
11:00pm10:30pm
00:0023:30
01:0000:30
02:0001:30
03:0002:30
04:0003:30
05:0004:30
06:0005:30
07:0006:30
08:0007:30
09:0008:30
10:0009:30
11:0010:30
12:0011:30
13:0012:30
14:0013:30
15:0014:30
16:0015:30
17:0016:30
18:0017:30
19:0018:30
20:0019:30
21:0020:30
22:0021:30
23:0022:30

Reunion Time

Offset: RET is 4 hours ahead Greenwich Mean Time (GMT) and is used in Africa

Countries using this time zone: Réunion

Principal Cities: The largest city in the RET time zone is Saint Denis in Reunion, with about 154,765 people. Other major cities in this time zone include Saint Paul, Saint Pierre, Le Tampon, Saint Andre.

Daylight Saving: Clocks in Reunion Time (RET) do not change for daylight saving time, so RET stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.

RET Time Zone Geo Map
RET timezone map

RET representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +04 - basic short
  • +0400 - basic
  • +04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0400 - sign character (+) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Delta - Military abbreviation for RET
  • D - short form of 'Delta'
Time zones with the GMT +4 offset:
  • KUYT - Kuybyshev Time
  • MSD - Moscow Daylight Time
  • SAMT - Samara Time
  • AMT - Armenia Time
  • AZT - Azerbaijan Time
  • D - Delta Time Zone
  • GET - Georgia Standard Time
  • GST - Gulf Standard Time
  • MUT - Mauritius Time
  • RET - Reunion Time
  • SCT - Seychelles Time

Iran Standard Time

Offset: IRST is 3 hours and 30 minutes ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: Iran

Principal Cities: The largest city in the IRST time zone is Tehran in Iran, with about 7.153 million people. Other major cities in this time zone include Mashhad, Isfahan, Karaj, Tabriz.

Daylight Saving: Clocks in Iran Standard Time (IRST) do not change for daylight saving time, so IRST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.

IRST Time Zone Geo Map
IRST timezone map

IRST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0330 - basic
  • +03:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0330 - sign character (+) followed by a four digit time providing hours (03) and minutes (30) of the offset. Indicates an offset of three hours and thirty minutes to the east of the zero meridian.