IRST to CET
-2h 30mIRST
IRSTSOURCECET
CETGreen rows indicate typical business hours (9 AM - 5 PM)
IRST and CET on the World Map
The map below highlights the IRST (Iran Standard Time) and CET (Central European Time) timezone regions across the globe.
IRST – Iran Standard Time
UTC+03:30Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.
- •IRST is one of only a few time zones with a 30-minute offset.
- •Iran observes daylight saving time, switching to IRDT (UTC+04:30).
- •Tehran has a metropolitan population of over 16 million.
CET – Central European Time
UTC+01:00Central European Time (CET) is used across most of Western and Central Europe, 1 hour ahead of UTC.
- •CET covers more European countries than any other time zone.
- •Spain uses CET despite being geographically aligned with GMT/WET.
- •The Frankfurt Stock Exchange, Euronext (Amsterdam/Paris), and Borsa Italiana operate on CET.
- •Over 500 million people live in the CET time zone.
- •France moved to CET during the German occupation in WWII and never switched back.
Understanding the -2h 30m Gap: IRST vs CET
IRST runs on Iran Standard Time (IRST) at UTC+03:30. CET runs on Central European Time (CET) at UTC+01:00. That puts IRST 2 hours 30 minutes behind CET — a difference of -2h 30m at the current offsets.
In practice, when it is 9:00 AM in IRST it is 6:30 AM in CET. Midnight in IRST is 9:30 PM in CET. Neither zone observes daylight saving time, so the offset between them stays constant all year.
IRST to CET time conversion table
| IRST (IRST) | CET (CET) | Day |
|---|---|---|
| 12:00 AM | 9:30 PM | previous day |
| 6:00 AM | 3:30 AM | same day |
| 7:00 AM | 4:30 AM | same day |
| 8:00 AM | 5:30 AM | same day |
| 9:00 AM | 6:30 AM | same day |
| 12:00 PM | 9:30 AM | same day |
| 3:00 PM | 12:30 PM | same day |
| 5:00 PM | 2:30 PM | same day |
| 6:00 PM | 3:30 PM | same day |
| 9:00 PM | 6:30 PM | same day |
Why people convert IRST to CET time
- Scheduling a call from IRST to CET: a 10:00 AM start in IRST lands at 7:30 AM in CET, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both IRST and CET are inside the 9-to-5 working day between 11:30 AM and 5:00 PM IRST time (9:00 AM–2:30 PM CET). That is roughly 5 hours 30 minutes of usable overlap.
- Coordinating a IRST-based team with CET contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a -2h 30m gap is not.
- Block 11:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need CET colleagues present.
About IRST (Iran Standard Time)
Iran Standard Time (IRST) is one of the few time zones with a 30-minute offset. Iran observes daylight saving time (IRDT, UTC+04:30) from late March to late September. Tehran, the capital, is one of the largest cities in the Middle East.
About CET (Central European Time)
Central European Time (CET) is the standard time zone for most of Europe, covering over 30 countries from Spain to Poland, and from Norway to Italy. CET is 1 hour ahead of GMT and is used by the European Union's most populous nations. During summer, most CET countries switch to Central European Summer Time (CEST, UTC+02:00). Major European financial markets in Frankfurt, Paris, and Amsterdam operate on CET.
Best time to call between IRST and CET
Both IRST and CET sit inside the 9 AM – 5 PM working day between 11:30 AM–5:00 PM IRST, which is 9:00 AM–2:30 PM CET. That gives roughly 5 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
IRST and CET share 5 hours of working-hours overlap (11:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.
IRST is 2 hours 30 minutes behind CET (IRST UTC+03:30 → CET UTC+01:00). The shared working window is 11:30 AM–5:00 PM IRST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
IRST
Does not observe DST
CET
☀ Currently in DST
Standard: UTC+01:00 · DST: UTC+02:00
Clocks fall back on Sun, Oct 25, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between IRST and CET?
IRST (IRST, UTC+03:30) is 2 hours 30 minutes behind CET (CET, UTC+01:00). The gap is currently -2h 30m.
How do I convert IRST time to CET time?
Add -2h 30m to IRST local time. For example, 9:00 AM in IRST is 6:30 AM in CET.
What time is it in CET right now?
CET uses CET at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -2h 30m offset from IRST.
What is the best time to call CET from IRST?
Call between 11:30 AM and 5:00 PM IRST — that maps to 9:00 AM–2:30 PM CET and keeps both parties inside the working day.
Which is behind, IRST or CET?
IRST is 2 hours 30 minutes behind CET. When it is 12:00 PM in IRST it is 9:30 AM in CET.
Does daylight saving time affect the IRST–CET difference?
Neither zone observes daylight saving time, so the -2h 30m offset between IRST and CET is fixed all year.
Which other cities share IRST's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, IRST's zone?
IRST is used in Iran.
Is there a day difference between IRST and CET?
Not normally. The -2h 30m gap only pushes the date over the previous day.
What is the time difference between IRST and CET?
CET is -2h 30m from IRST.
What timezone is IRST in?
IRST operates on its local timezone.
What timezone is CET in?
CET operates on its local timezone.
Which countries use IRST (Iran Standard Time)?
IRST is used in Iran.
Does IRST observe daylight saving time?
Yes, IRST switches to IRDT during summer months.
What are some interesting facts about IRST?
IRST is one of only a few time zones with a 30-minute offset. Iran observes daylight saving time, switching to IRDT (UTC+04:30).
Which cities are in the CET timezone?
Major cities in the CET timezone include Paris, Berlin, Rome, Madrid, Amsterdam, Brussels, Vienna, Warsaw.
What is the UTC offset for CET?
Central European Time (CET) is at UTC+01:00. During daylight saving time, it shifts to CEST.
What should I know about the CET timezone?
CET covers more European countries than any other time zone. Spain uses CET despite being geographically aligned with GMT/WET.
When is it midnight in IRST, what time is it in CET?
When it is 12:00 AM (midnight) in IRST (IRST), it is -2h 30m later in CET (CET).
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