Does it handle Daylight Saving Time?

Yes, the tool automatically adjusts for Daylight Saving Time based on the specific date you select, ensuring accurate conversions year-round.

Can I add multiple cities?

Yes, you can add as many cities as you need to the dashboard to compare times across your entire global network simultaneously.

IRST to CEST

-1h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

CEST

UTC+02:00☀ DST active

HH10

MM30

10:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

CEST

12:00 AM

10:30 PM-1

2:00 AM

12:30 AM

4:00 AM

2:30 AM

6:00 AM

4:30 AM

8:00 AM

6:30 AM

10:00 AM

8:30 AM

12:00 PM

10:30 AM

2:00 PM

12:30 PM

4:00 PM

2:30 PM

6:00 PM

4:30 PM

8:00 PM

6:30 PM

10:00 PM

8:30 PM

Green rows indicate typical business hours (9 AM - 5 PM)

IRST and CEST on the World Map

The map below highlights the IRST (Iran Standard Time) and CEST (Central European Summer Time) timezone regions across the globe.

IRST Zone

→

CEST Zone

Explore all world timezones interactively →

IRST – Iran Standard Time

UTC+03:30

Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.

Countries in IRST

Iran

Major Cities in IRST

TehranIsfahanMashhadTabrizShirazKaraj

Key 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).
•Tehran has a metropolitan population of over 16 million.

Daylight Saving:Yes – switches to IRDT

Learn more about IRST on Wikipedia

CEST – Central European Summer Time

UTC+02:00

Central European Summer Time (CEST) is the daylight saving time in Central Europe, 2 hours ahead of UTC.

Countries in CEST

GermanyFranceItalySpainNetherlandsBelgiumAustriaSwitzerlandPolandSwedenNorway

Major Cities in CEST

ParisBerlinRomeMadridAmsterdamViennaStockholm

Key Facts about CEST

•CEST runs from the last Sunday of March to the last Sunday of October.
•The EU has voted to abolish clock changes but implementation has been delayed.
•CEST shares the same offset as EET (UTC+02:00).

Daylight Saving:Yes – switches to CET

Learn more about CEST on Wikipedia

IRST to CEST Time Difference – Complete Guide

IRST runs on Iran Standard Time (IRST) at UTC+03:30. CEST runs on Central European Summer Time (CEST) at UTC+02:00. That puts IRST 1 hour 30 minutes behind CEST — a difference of -1h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 7:30 AM in CEST. Midnight in IRST is 10:30 PM in CEST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to CEST time conversion table

IRST (IRST)	CEST (CEST)	Day
12:00 AM	10:30 PM	previous day
6:00 AM	4:30 AM	same day
7:00 AM	5:30 AM	same day
8:00 AM	6:30 AM	same day
9:00 AM	7:30 AM	same day
12:00 PM	10:30 AM	same day
3:00 PM	1:30 PM	same day
5:00 PM	3:30 PM	same day
6:00 PM	4:30 PM	same day
9:00 PM	7:30 PM	same day

Why people convert IRST to CEST time

Scheduling a call from IRST to CEST: a 10:00 AM start in IRST lands at 8:30 AM in CEST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and CEST are inside the 9-to-5 working day between 10:30 AM and 5:00 PM IRST time (9:00 AM–3:30 PM CEST). That is roughly 6 hours 30 minutes of usable overlap.
Coordinating a IRST-based team with CEST 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 -1h 30m gap is not.
Block 10:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need CEST 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 CEST (Central European Summer Time)

Central European Summer Time (CEST) is observed from the last Sunday of March to the last Sunday of October across most of Europe. During CEST, clocks are 2 hours ahead of UTC. The EU has debated abolishing seasonal clock changes since 2019.

Best time to call between IRST and CEST

Both IRST and CEST sit inside the 9 AM – 5 PM working day between 10:30 AM–5:00 PM IRST, which is 9:00 AM–3:30 PM CEST. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and CEST share 6 hours of working-hours overlap (10:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.

IRST is 1 hour 30 minutes behind CEST (IRST UTC+03:30 → CEST UTC+02:00). The shared working window is 10:30 AM–5:00 PM IRST. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

IRST

Does not observe DST

CEST

☀ 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:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between IRST and CEST?

IRST (IRST, UTC+03:30) is 1 hour 30 minutes behind CEST (CEST, UTC+02:00). The gap is currently -1h 30m.

How do I convert IRST time to CEST time?

Add -1h 30m to IRST local time. For example, 9:00 AM in IRST is 7:30 AM in CEST.

What time is it in CEST right now?

CEST uses CEST at UTC+02:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -1h 30m offset from IRST.