Ireland to Tehran
+2h 30mIreland
ISTSOURCETehran
IRSTGreen rows indicate typical business hours (9 AM - 5 PM)
IST and IRST on the World Map
The map below highlights the IST (Greenwich Mean Time) and IRST (Iran Standard Time) timezone regions across the globe.
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
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.
About Tehran
WikipediaTehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).
Everything You Need to Know About Ireland and Tehran Time
Ireland runs on Irish Standard Time (IST) at UTC+01:00, currently observing daylight saving time. Tehran runs on Iran Standard Time (IRST) at UTC+03:30. That puts Ireland 2 hours 30 minutes ahead of Tehran — a difference of +2h 30m at the current offsets.
In practice, when it is 9:00 AM in Ireland it is 11:30 AM in Tehran. Midnight in Ireland is 2:30 AM in Tehran.Ireland observes daylight saving time while Tehran does not, so the gap narrows or widens by an hour part of the year.
Ireland to Tehran time conversion table
| Ireland (IST) | Tehran (IRST) | Day |
|---|---|---|
| 12:00 AM | 2:30 AM | same day |
| 6:00 AM | 8:30 AM | same day |
| 7:00 AM | 9:30 AM | same day |
| 8:00 AM | 10:30 AM | same day |
| 9:00 AM | 11:30 AM | same day |
| 12:00 PM | 2:30 PM | same day |
| 3:00 PM | 5:30 PM | same day |
| 5:00 PM | 7:30 PM | same day |
| 6:00 PM | 8:30 PM | same day |
| 9:00 PM | 11:30 PM | same day |
Why people convert Ireland to Tehran time
- Scheduling a call from Ireland to Tehran: a 10:00 AM start in Ireland lands at 12:30 PM in Tehran, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Ireland and Tehran are inside the 9-to-5 working day between 9:00 AM and 2:30 PM IST time (11:30 AM–5:00 PM IRST). That is roughly 5 hours 30 minutes of usable overlap.
- Coordinating a Ireland-based team with Tehran 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 IST" is unambiguous; "3 PM" across a +2h 30m gap is not.
- Block 9:00 AM–2:30 PM IST as the recurring meeting window if you work primarily from Ireland and need Tehran colleagues present.
- Ireland: Clocks fall back on Sun, Oct 25, 2026. Re-check this page after that date because the offset changes and so does the +2h 30m gap.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
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.
Best time to call between Ireland and Tehran
Both Ireland and Tehran sit inside the 9 AM – 5 PM working day between 9:00 AM–2:30 PM IST, which is 11:30 AM–5:00 PM IRST. That gives roughly 5 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Ireland and Tehran share 5 hours of working-hours overlap (9:00 AM–2:30 PM IST), so scheduling a live meeting is straightforward.
Ireland is 2 hours 30 minutes ahead of Tehran (IST UTC+01:00 → IRST UTC+03:30). The shared working window is 9:00 AM–2:30 PM IST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Ireland
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
Tehran
Does not observe DST
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 Ireland and Tehran?
Ireland (IST, UTC+01:00) is 2 hours 30 minutes ahead of Tehran (IRST, UTC+03:30). The gap is currently +2h 30m.
How do I convert Ireland time to Tehran time?
Add +2h 30m to Ireland local time. For example, 9:00 AM in Ireland is 11:30 AM in Tehran.
What time is it in Tehran right now?
Tehran uses IRST at UTC+03:30. Use the live converter at the top of this page — it updates in real time and already accounts for the +2h 30m offset from Ireland.
What is the best time to call Tehran from Ireland?
Call between 9:00 AM and 2:30 PM IST — that maps to 11:30 AM–5:00 PM IRST and keeps both parties inside the working day.
Which is ahead, Ireland or Tehran?
Ireland is 2 hours 30 minutes ahead of Tehran. When it is 12:00 PM in Ireland it is 2:30 PM in Tehran.
Do Ireland and Tehran use different time zones?
Ireland (Ireland) uses IST at UTC+01:00, while Tehran (Iran) uses IRST at UTC+03:30. The IANA identifiers are Europe/Dublin and Asia/Tehran.
Does daylight saving time affect the Ireland–Tehran difference?
Yes at the moment: Ireland is on daylight saving time and Tehran is not, so the +2h 30m gap shifts by an hour when exactly one of them changes clocks.
Which other cities share Ireland's time zone?
IST also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.
Which countries use IST, Ireland's zone?
IST is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.
Is there a day difference between Ireland and Tehran?
Not normally. The +2h 30m gap only pushes the date over for late-evening times.
What is the time difference between Ireland and Tehran?
Tehran is +2h 30m from Ireland.
What timezone is Ireland in?
Ireland operates on its local timezone.
What timezone is Tehran in?
Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
What are the business hours in Tehran?
Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.
Which countries use GMT (Greenwich Mean Time)?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.
Does GMT observe daylight saving time?
Yes, GMT switches to BST during summer months.
What are some interesting facts about GMT?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
Which cities are in the IRST timezone?
Major cities in the IRST timezone include Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
What is the UTC offset for IRST?
Iran Standard Time (IRST) is at UTC+03:30. During daylight saving time, it shifts to IRDT.
What should I know about the IRST timezone?
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).
When is it midnight in Ireland, what time is it in Tehran?
When it is 12:00 AM (midnight) in Ireland (GMT), it is +2h 30m later in Tehran (IRST).
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