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D
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IRST/IRDT
UTC+3:30
30m behind
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IRDT is not used on this date.

This converter uses IRST (UTC+3:30), as in Tehran.

Quick answers

Selected conversion

4:00 pm16:00 D (UTC+4), Oct 17, 2026 = 3:30 pm15:30 IRST (UTC+3:30), Oct 17, 2026

D is 30 minutes ahead of IRST.

D and IRDT examples

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

D is 30 minutes behind IRDT.

How the time difference changes

D is 30 minutes ahead of IRST year-round.

Working hours of 9:00 am to 6:00 pm in D correspond to 8:30 am to 5:30 pm in IRST.Working hours of 09:00 to 18:00 in D correspond to 08:30 to 17:30 in IRST.

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

Time Difference

Delta Time Zone is 30 minutes ahead of Iran Standard Time.
4:00 pm16:00 in D is 3:30 pm15:30 in IRST

D to IRST call time
Best time for a conference call or a meeting is between 9:30am-6pm09:30-18:00 in D which corresponds to 9am-5:30pm09:00-17:30 in IRST

4:00 pm16:00 Delta Time Zone (D). Offset UTC +4:00 hours
3:30 pm15:30 Iran Standard Time (IRST). Offset UTC +3:30 hours

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

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Hourly time comparison
DIRST
11:30pm previous day
12:30am
1:30am
2:30am
3:30am
4:30am
5:30am
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12:30pm
1:30pm
2:30pm
3:30pm
4:30pm
5:30pm
6:30pm
7:30pm
8:30pm
9:30pm
10:30pm
23:30 previous day
00:30
01:30
02:30
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Delta Time Zone

Offset: D is 4 hours ahead of Greenwich Mean Time (GMT).

Countries using this time zone: Armenia, Azerbaijan, Georgia, Mauritius, Oman, Réunion, Russia, Seychelles, United Arab Emirates

Principal Cities: The largest city in the D time zone is Dubai in the United Arab Emirates, with about 3.79 million people. Other major cities in this time zone include Baku, Abu Dhabi, Sharjah, Samara.

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

D 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 D
  • 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 Daylight Time

Offset: IRDT is 4 hours and 30 minutes ahead of Greenwich Mean Time (GMT).

IRDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +0430 - basic
  • +04:30 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0430 - sign character (+) followed by a four digit time providing hours (04) and minutes (30) of the offset. Indicates an offset of four hours and thirty minutes to the east of the zero meridian.
Time zones with the GMT +4:30 offset:
  • AFT - Afghanistan Time
  • IRDT - Iran Daylight Time