Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

IRST to UTC

Q: What is UTC?

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

-3h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

UTC

UTC+00:00

HH08

MM30

08:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

UTC

12:00 AM

8:30 PM-1

2:00 AM

10:30 PM-1

4:00 AM

12:30 AM

6:00 AM

2:30 AM

8:00 AM

4:30 AM

10:00 AM

6:30 AM

12:00 PM

8:30 AM

2:00 PM

10:30 AM

4:00 PM

12:30 PM

6:00 PM

2:30 PM

8:00 PM

4:30 PM

10:00 PM

6:30 PM

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

IRST and UTC on the World Map

The map below highlights the IRST (Iran Standard Time) and UTC (Coordinated Universal Time) timezone regions across the globe.

IRST Zone

→

UTC 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

UTC – Coordinated Universal Time

UTC+00:00

Coordinated Universal Time (UTC) is the world's primary time standard, used as the basis for civil time worldwide.

Countries in UTC

Used worldwide as referenceSame zone as: UK, Ireland, Iceland, Portugal, Ghana

Major Cities in UTC

LondonDublinReykjavikAccraLisbonDakar

Key Facts about UTC

•UTC is the basis for all civil time zones worldwide.
•The abbreviation 'UTC' is a compromise between English (CUT) and French (TUC).
•UTC is based on atomic clocks and is accurate to within a nanosecond per day.
•Servers and databases worldwide store timestamps in UTC to avoid timezone confusion.
•Leap seconds are occasionally added to UTC to keep it aligned with Earth's rotation.

Daylight Saving:No – UTC+00:00 year-round

Learn more about UTC on Wikipedia

IRST vs UTC: Offsets, DST and Best Call Times

IRST runs on Iran Standard Time (IRST) at UTC+03:30. UTC runs on Coordinated Universal Time (UTC) at UTC+00:00. That puts IRST 3 hours 30 minutes behind UTC — a difference of -3h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 5:30 AM in UTC. Midnight in IRST is 8:30 PM in UTC. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to UTC time conversion table

IRST (IRST)	UTC (UTC)	Day
12:00 AM	8:30 PM	previous day
6:00 AM	2:30 AM	same day
7:00 AM	3:30 AM	same day
8:00 AM	4:30 AM	same day
9:00 AM	5:30 AM	same day
12:00 PM	8:30 AM	same day
3:00 PM	11:30 AM	same day
5:00 PM	1:30 PM	same day
6:00 PM	2:30 PM	same day
9:00 PM	5:30 PM	same day

Why people convert IRST to UTC time

Scheduling a call from IRST to UTC: a 10:00 AM start in IRST lands at 6:30 AM in UTC, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and UTC are inside the 9-to-5 working day between 12:30 PM and 5:00 PM IRST time (9:00 AM–1:30 PM UTC). That is roughly 4 hours 30 minutes of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in IRST is 4:30 PM in UTC makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a -3h 30m gap is not.
Block 12:30 PM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need UTC 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 UTC (Coordinated Universal Time)

Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time. It is effectively the successor to GMT and is based on International Atomic Time with leap seconds added to keep it synchronized with Earth's rotation. UTC is used in aviation, computing, navigation, weather forecasting, and the International Space Station. Most programming languages and databases store timestamps in UTC.

Best time to call between IRST and UTC

Both IRST and UTC sit inside the 9 AM – 5 PM working day between 12:30 PM–5:00 PM IRST, which is 9:00 AM–1:30 PM UTC. That gives roughly 4 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and UTC overlap for about 4 hours during the working day — enough for meetings if you avoid the edges of the window.

IRST is 3 hours 30 minutes behind UTC (IRST UTC+03:30 → UTC UTC+00:00). The shared working window is 12:30 PM–5:00 PM IRST. Remember to re-check around daylight-saving transitions.

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 UTC?

IRST (IRST, UTC+03:30) is 3 hours 30 minutes behind UTC (UTC, UTC+00:00). The gap is currently -3h 30m.

How do I convert IRST time to UTC time?

Add -3h 30m to IRST local time. For example, 9:00 AM in IRST is 5:30 AM in UTC.

What time is it in UTC right now?

UTC uses UTC at UTC+00:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -3h 30m offset from IRST.