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).

Istanbul to IRST

+0h 30m

Istanbul

TRTSOURCE

Turkey · UTC+03:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

IRST

UTC+03:30

HH12

MM30

12:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Istanbul

IRST

12:00 AM

12:30 AM

2:00 AM

2:30 AM

4:00 AM

4:30 AM

6:00 AM

6:30 AM

8:00 AM

8:30 AM

10:00 AM

10:30 AM

12:00 PM

12:30 PM

2:00 PM

2:30 PM

4:00 PM

4:30 PM

6:00 PM

6:30 PM

8:00 PM

8:30 PM

10:00 PM

10:30 PM

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

TRT and IRST on the World Map

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

TRT Zone

→

IRST Zone

Explore all world timezones interactively →

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

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

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 →

Istanbul vs IRST: Offsets, DST and Best Call Times

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

In practice, when it is 9:00 AM in Istanbul it is 9:30 AM in IRST. Midnight in Istanbul is 12:30 AM in IRST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Istanbul to IRST time conversion table

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

Why people convert Istanbul to IRST time

Scheduling a call from Istanbul to IRST: a 10:00 AM start in Istanbul lands at 10:30 AM in IRST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Istanbul and IRST are inside the 9-to-5 working day between 9:00 AM and 4:30 PM TRT time (9:30 AM–5:00 PM IRST). That is roughly 7 hours 30 minutes of usable overlap.
Coordinating a Istanbul-based team with IRST 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 TRT" is unambiguous; "3 PM" across a +0h 30m gap is not.
Block 9:00 AM–4:30 PM TRT as the recurring meeting window if you work primarily from Istanbul and need IRST colleagues present.

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.

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 Istanbul and IRST

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

Business hours overlap

Istanbul and IRST share 7 hours of working-hours overlap (9:00 AM–4:30 PM TRT), so scheduling a live meeting is straightforward.

Istanbul is 30 minutes ahead of IRST (TRT UTC+03:00 → IRST UTC+03:30). The shared working window is 9:00 AM–4:30 PM TRT. 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 Istanbul and IRST?

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

How do I convert Istanbul time to IRST time?

Add +0h 30m to Istanbul local time. For example, 9:00 AM in Istanbul is 9:30 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 +0h 30m offset from Istanbul.

What is the best time to call IRST from Istanbul?

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

Which is ahead, Istanbul or IRST?

Istanbul is 30 minutes ahead of IRST. When it is 12:00 PM in Istanbul it is 12:30 PM in IRST.

Do Istanbul and IRST use different time zones?

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

Does daylight saving time affect the Istanbul–IRST difference?

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

Which other cities share Istanbul's time zone?

TRT also covers Istanbul, Ankara, Izmir, Bursa, Antalya.

Which countries use TRT, Istanbul's zone?

TRT is used in Turkey.

Is there a day difference between Istanbul and IRST?

Not normally. The +0h 30m gap only pushes the date over for late-evening times.

What is the time difference between Istanbul and IRST?

IRST is +0h 30m from Istanbul.

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 timezone is IRST in?

IRST operates on its local timezone.

What are the business hours in Istanbul?

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

Which countries use TRT (Turkey Time)?

TRT is used in Turkey.

Does TRT observe daylight saving time?

No, TRT does not observe daylight saving time and remains at UTC+03:00 year-round.

What are some interesting 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.

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 Istanbul, what time is it in IRST?

When it is 12:00 AM (midnight) in Istanbul (TRT), it is +0h 30m later in IRST (IRST).

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Istanbul to IRST

Istanbul

IRST

TRT and IRST on the World Map

TRT – Turkey Time

IRST – Iran Standard Time

About Istanbul

Istanbul vs IRST: Offsets, DST and Best Call Times

Istanbul to IRST time conversion table

Why people convert Istanbul to IRST time

About TRT (Turkey Time)

About IRST (Iran Standard Time)

Best time to call between Istanbul and IRST

Business hours overlap

Learn More About Time

Frequently Asked Questions

What is the time difference between Istanbul and IRST?

How do I convert Istanbul time to IRST time?

What time is it in IRST right now?

What is the best time to call IRST from Istanbul?

Which is ahead, Istanbul or IRST?

Do Istanbul and IRST use different time zones?

Does daylight saving time affect the Istanbul–IRST difference?

Which other cities share Istanbul's time zone?

Which countries use TRT, Istanbul's zone?

Is there a day difference between Istanbul and IRST?

What is the time difference between Istanbul and IRST?

What timezone is Istanbul in?

What timezone is IRST in?

What are the business hours in Istanbul?

Which countries use TRT (Turkey Time)?

Does TRT observe daylight saving time?

What are some interesting facts about TRT?

Which cities are in the IRST timezone?

What is the UTC offset for IRST?

What should I know about the IRST timezone?

When is it midnight in Istanbul, what time is it in IRST?

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