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.

Dublin to IRST

+2h 30m

Dublin

ISTSOURCE

Ireland · UTC+01:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

IRST

UTC+03:30

HH02

MM30

14:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Dublin

IRST

12:00 AM

2:30 AM

2:00 AM

4:30 AM

4:00 AM

6:30 AM

6:00 AM

8:30 AM

8:00 AM

10:30 AM

10:00 AM

12:30 PM

12:00 PM

2:30 PM

2:00 PM

4:30 PM

4:00 PM

6:30 PM

6:00 PM

8:30 PM

8:00 PM

10:30 PM

10:00 PM

12:30 AM+1

Green 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.

IST Zone

→

IRST Zone

Explore all world timezones interactively →

GMT – Greenwich Mean Time

UTC+00:00

Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.

Countries in GMT

United KingdomIrelandIcelandPortugal (mainland)GhanaSenegalMaliMauritaniaGambiaGuineaSierra LeoneLiberiaIvory CoastBurkina FasoMorocco (historically)

Major Cities in GMT

LondonDublinLisbonAccraReykjavikEdinburghCasablancaDakarBamakoAbidjanConakryFreetownMonrovia

Key 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.
•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.

Daylight Saving:Yes – switches to BST

Learn more about GMT on Wikipedia

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

Dublin vs IRST: Offsets, DST and Best Call Times

Dublin runs on Irish Standard Time (IST) at UTC+01:00, currently observing daylight saving time. IRST runs on Iran Standard Time (IRST) at UTC+03:30. That puts Dublin 2 hours 30 minutes ahead of IRST — a difference of +2h 30m at the current offsets.

In practice, when it is 9:00 AM in Dublin it is 11:30 AM in IRST. Midnight in Dublin is 2:30 AM in IRST.Dublin observes daylight saving time while IRST does not, so the gap narrows or widens by an hour part of the year.

Dublin to IRST time conversion table

Dublin (IST)	IRST (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 Dublin to IRST time

Scheduling a call from Dublin to IRST: a 10:00 AM start in Dublin lands at 12:30 PM in IRST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Dublin and IRST 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.
Keeping family and friends in sync: knowing that 8:00 PM in Dublin is 10:30 PM in IRST makes it easy to avoid calling at 3 AM.

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 Dublin and need IRST colleagues present.
Dublin: 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 Dublin and IRST

Both Dublin and IRST 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

Dublin and IRST share 5 hours of working-hours overlap (9:00 AM–2:30 PM IST), so scheduling a live meeting is straightforward.

Dublin is 2 hours 30 minutes ahead of IRST (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

Dublin

☀ Currently in DST

Standard: UTC+00:00 · DST: UTC+01:00

Clocks fall back on Sun, Oct 25, 2026

IRST

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:

⏳

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 Dublin and IRST?

Dublin (IST, UTC+01:00) is 2 hours 30 minutes ahead of IRST (IRST, UTC+03:30). The gap is currently +2h 30m.

How do I convert Dublin time to IRST time?

Add +2h 30m to Dublin local time. For example, 9:00 AM in Dublin is 11:30 AM in IRST.

What time is it in IRST right now?

IRST 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 Dublin.

What is the best time to call IRST from Dublin?

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, Dublin or IRST?

Dublin is 2 hours 30 minutes ahead of IRST. When it is 12:00 PM in Dublin it is 2:30 PM in IRST.

Do Dublin and IRST use different time zones?

Dublin (Ireland) uses IST at UTC+01:00, while IRST uses IRST at UTC+03:30. The IANA identifiers are Europe/Dublin and Asia/Tehran.

Does daylight saving time affect the Dublin–IRST difference?

Yes at the moment: Dublin is on daylight saving time and IRST is not, so the +2h 30m gap shifts by an hour when exactly one of them changes clocks.

Which other cities share Dublin's time zone?

IST also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.

Which countries use IST, Dublin'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 Dublin and IRST?

Not normally. The +2h 30m gap only pushes the date over for late-evening times.

What is the time difference between Dublin and IRST?

IRST is +2h 30m from Dublin.

What timezone is Dublin in?

Dublin operates on its local timezone.

What timezone is IRST in?

IRST operates on its local timezone.

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.