D to IRST Converter
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Quick answers
Selected conversion
4:00 pm16:00 D (UTC+4), Oct 13, 2026 = 3:30 pm15:30 IRST (UTC+3:30), Oct 13, 2026
D is 30 minutes ahead of IRST.
D and IRST examples
These examples always use D (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.
D is 30 minutes ahead of IRST.
How the time difference changes
D is 30 minutes ahead of IRST year-round.
Working hours of 9:00 am to 5:00 pm in D correspond to 8:30 am to 4:30 pm in IRST.Working hours of 09:00 to 17:00 in D correspond to 08:30 to 16:30 in IRST.
Compare D time with IRST 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-5pm09:30-17:00 in D which corresponds to 9am-4:30pm09:00-16:30 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
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
| D | IRST |
|---|---|
| 11:30pm previous day | |
| 12:30am | |
| 1:30am | |
| 2:30am | |
| 3:30am | |
| 4:30am | |
| 5:30am | |
| 6:30am | |
| 7:30am | |
| 8:30am | |
| 9:30am | |
| 10:30am | |
| 11:30am | |
| 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 | |
| 03:30 | |
| 04:30 | |
| 05:30 | |
| 06:30 | |
| 07:30 | |
| 08:30 | |
| 09:30 | |
| 10:30 | |
| 11:30 | |
| 12:30 | |
| 13:30 | |
| 14:30 | |
| 15:30 | |
| 16:30 | |
| 17:30 | |
| 18:30 | |
| 19:30 | |
| 20:30 | |
| 21:30 | |
| 22:30 |
Delta Time Zone
Offset: D is 4 hours ahead of Greenwich Mean Time (GMT).
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
- +04 - basic short
- +0400 - basic
- +04:00 - extended
- +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.
- Delta - Military abbreviation for D
- D - short form of 'Delta'
- 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 of Greenwich Mean Time (GMT).
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 representations, usage and related time zones
- +0330 - basic
- +03:30 - extended
- +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.