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.

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

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).

Tehran to Istanbul

-0h 30m

Tehran

IRSTSOURCE

Iran · UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Istanbul

TRT

Turkey · UTC+03:00

HH11

MM30

11:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Tehran

Istanbul

12:00 AM

11:30 PM-1

2:00 AM

1:30 AM

4:00 AM

3:30 AM

6:00 AM

5:30 AM

8:00 AM

7:30 AM

10:00 AM

9:30 AM

12:00 PM

11:30 AM

2:00 PM

1:30 PM

4:00 PM

3:30 PM

6:00 PM

5:30 PM

8:00 PM

7:30 PM

10:00 PM

9:30 PM

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

IRST and TRT on the World Map

The map below highlights the IRST (Iran Standard Time) and TRT (Turkey Time) timezone regions across the globe.

IRST Zone

→

TRT 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

TRT – Turkey Time

UTC+03:00

Turkey Time (TRT, UTC+03:00) is the single time zone used across Turkey, fixed year round since 2016.

Countries in TRT

Turkey

Major Cities in TRT

IstanbulAnkaraIzmirBursaAntalya

Key Facts about TRT

•Turkey has used a permanent UTC+03:00 since September 2016.
•TRT is level with Moscow Standard Time and Arabia Standard Time all year.
•Because Turkey kept summer time permanently, western cities see very late winter sunrises.
•Turkey previously observed daylight saving time from 1973 to 2016.

Daylight Saving:No – UTC+03:00 year-round

Learn more about TRT on Wikipedia

About Tehran

Wikipedia

Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.

Population:9.4 million

Metro:16.8 million

Business Hours:8:00 AM - 4:00 PM IRST

Currency:IRR (﷼)

Stock Exchange:TSE (Tehran Stock Exchange)

Key Landmarks

Azadi TowerGolestan PalaceGrand BazaarMilad TowerTabiat Bridge

Did You Know?

Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).

Learn more about IRST timezone →

About Istanbul

Wikipedia

Istanbul operates on Turkey Time (TRT), UTC+3 year-round. As a transcontinental city, Istanbul bridges European and Asian business hours.

Population:15.5 million

Metro:15.8 million

Business Hours:9:00 AM - 6:00 PM TRT

Currency:TRY (₺)

Stock Exchange:Borsa Istanbul

Key Landmarks

Hagia SophiaBlue MosqueTopkapi PalaceGrand BazaarGalata Tower

Did You Know?

The Grand Bazaar is one of the world's oldest and largest covered markets with 4,000+ shops.

Learn more about TRT timezone →

Understanding the -0h 30m Gap: Tehran vs Istanbul

Tehran runs on Iran Standard Time (IRST) at UTC+03:30. Istanbul runs on Türkiye Standard Time (TRT) at UTC+03:00. That puts Tehran 30 minutes behind Istanbul — a difference of -0h 30m at the current offsets.

In practice, when it is 9:00 AM in Tehran it is 8:30 AM in Istanbul. Midnight in Tehran is 11:30 PM in Istanbul. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Tehran to Istanbul time conversion table

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

Why people convert Tehran to Istanbul time

Scheduling a call from Tehran to Istanbul: a 10:00 AM start in Tehran lands at 9:30 AM in Istanbul, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Tehran and Istanbul are inside the 9-to-5 working day between 9:30 AM and 5:00 PM IRST time (9:00 AM–4:30 PM TRT). That is roughly 7 hours 30 minutes of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in Tehran is 7:30 PM in Istanbul 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 -0h 30m gap is not.
Block 9:30 AM–5:00 PM IRST as the recurring meeting window if you work primarily from Tehran and need Istanbul 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 TRT (Turkey Time)

Turkey Time (TRT) is fixed at UTC+03:00 all year. Turkey abolished seasonal clock changes in September 2016, moving to a permanent UTC+03:00 so the whole country stays on what was formerly summer time. That leaves Istanbul, which sits close to 29°E, on an offset well ahead of its solar time — sunrise in mid-winter comes after 08:30 local. TRT shares its offset with Moscow Standard Time, Arabia Standard Time and East Africa Time, so Istanbul is level with Moscow and Riyadh all year and one hour ahead of Central European Time during the European winter.

Best time to call between Tehran and Istanbul

Both Tehran and Istanbul sit inside the 9 AM – 5 PM working day between 9:30 AM–5:00 PM IRST, which is 9:00 AM–4:30 PM TRT. That gives roughly 7 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

Tehran and Istanbul share 7 hours of working-hours overlap (9:30 AM–5:00 PM IRST), so scheduling a live meeting is straightforward.

Tehran is 30 minutes behind Istanbul (IRST UTC+03:30 → TRT UTC+03:00). The shared working window is 9:30 AM–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 Tehran and Istanbul?

Tehran (IRST, UTC+03:30) is 30 minutes behind Istanbul (TRT, UTC+03:00). The gap is currently -0h 30m.

How do I convert Tehran time to Istanbul time?

Add -0h 30m to Tehran local time. For example, 9:00 AM in Tehran is 8:30 AM in Istanbul.

What time is it in Istanbul right now?

Istanbul uses TRT at UTC+03:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -0h 30m offset from Tehran.

What is the best time to call Istanbul from Tehran?

Call between 9:30 AM and 5:00 PM IRST — that maps to 9:00 AM–4:30 PM TRT and keeps both parties inside the working day.

Which is behind, Tehran or Istanbul?

Tehran is 30 minutes behind Istanbul. When it is 12:00 PM in Tehran it is 11:30 AM in Istanbul.

Do Tehran and Istanbul use different time zones?

Tehran (Iran) uses IRST at UTC+03:30, while Istanbul (Turkey) uses TRT at UTC+03:00. The IANA identifiers are Asia/Tehran and Europe/Istanbul.

Does daylight saving time affect the Tehran–Istanbul difference?

Neither zone observes daylight saving time, so the -0h 30m offset between Tehran and Istanbul is fixed all year.

Which other cities share Tehran's time zone?

IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.

Which countries use IRST, Tehran's zone?

IRST is used in Iran.

Is there a day difference between Tehran and Istanbul?

Not normally. The -0h 30m gap only pushes the date over the previous day.

What is the time difference between Tehran and Istanbul?

Istanbul is -0h 30m from Tehran.

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 timezone is Istanbul in?

Istanbul operates on Turkey Time (TRT), UTC+3 year-round. As a transcontinental city, Istanbul bridges European and Asian business hours.

What are the business hours in Tehran?

Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.

What are the business hours in Istanbul?

Standard business hours in Istanbul are 9:00 AM - 6:00 PM TRT.

What is the best time to schedule a call between Tehran and Istanbul?

The best overlap for a call is when both cities are in business hours. Tehran works 8:00 AM - 4:00 PM IRST and Istanbul works 9:00 AM - 6:00 PM TRT (-0h 30m difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Tehran and Istanbul?

Tehran uses IRR (﷼) while Istanbul uses TRY (₺). Check current exchange rates when planning travel or business between these cities.

How do Tehran and Istanbul compare in size?

Tehran has a population of approximately 9.4 million (metro: 16.8 million), while Istanbul has approximately 15.5 million (metro: 15.8 million).

What are the major landmarks in Tehran and Istanbul?

Tehran is known for Azadi Tower, Golestan Palace, Grand Bazaar. Istanbul is famous for Hagia Sophia, Blue Mosque, Topkapi Palace.

Do Tehran and Istanbul have stock exchanges?

Yes. Tehran has the TSE (Tehran Stock Exchange) and Istanbul has the Borsa Istanbul. The -0h 30m time difference affects trading hour overlaps between these exchanges.