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).

EST to Tehran

+8h 30m

EST

ESTSOURCE

UTC-04:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Tehran

IRST

Iran · UTC+03:30

HH08

MM30

20:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

EST

Tehran

12:00 AM

7:30 AM

2:00 AM

9:30 AM

4:00 AM

11:30 AM

6:00 AM

1:30 PM

8:00 AM

3:30 PM

10:00 AM

5:30 PM

12:00 PM

7:30 PM

2:00 PM

9:30 PM

4:00 PM

11:30 PM

6:00 PM

1:30 AM+1

8:00 PM

3:30 AM+1

10:00 PM

5:30 AM+1

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

EST and IRST on the World Map

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

EST Zone

→

IRST Zone

Explore all world timezones interactively →

EST – Eastern Standard Time

UTC-05:00

Eastern Standard Time (EST) is the time zone for the eastern United States and Canada, 5 hours behind UTC.

Countries in EST

United States (Eastern)Canada (Ontario, Quebec)Mexico (Quintana Roo)PanamaJamaicaCayman IslandsHaitiBahamasTurks and CaicosColombiaPeruEcuador

Major Cities in EST

New York CityWashington D.C.MiamiTorontoPhiladelphiaAtlantaBostonMontrealDetroitCharlotteIndianapolisOttawaTampaOrlandoClevelandPittsburgh

Key Facts about EST

•EST is the most widely used time zone in the United States by population.
•The New York Stock Exchange (NYSE) and NASDAQ operate on Eastern Time, opening at 9:30 AM EST.
•23 US states are fully or partially in the Eastern Time Zone.
•EST was established by the Standard Time Act of 1918.
•Over 47% of the US population lives in the Eastern Time Zone.

Daylight Saving:Yes – switches to EDT

Learn more about EST 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 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 →

Understanding the +8h 30m Gap: EST vs Tehran

EST runs on Eastern Standard Time (EST) at UTC-05:00. Tehran runs on Iran Standard Time (IRST) at UTC+03:30. That puts EST 8 hours 30 minutes ahead of Tehran — a difference of +8h 30m at the current offsets.

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

EST to Tehran time conversion table

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

Why people convert EST to Tehran time

Scheduling a call from EST to Tehran: a 10:00 AM start in EST lands at 6:30 PM in Tehran, so you can confirm the slot without doing the arithmetic yourself.
Handling a +8h 30m gap: EST and Tehran have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in Tehran is 5:30 PM in EST.
Booking travel or deliveries: tracking Tehran local time against EST keeps pickup windows and arrival estimates honest across the +8h 30m offset.

Always state the zone abbreviation, not just the hour. "3:00 PM EST" is unambiguous; "3 PM" across a +8h 30m gap is not.
With a +8h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week EST takes the early slot, the next week Tehran does.

About EST (Eastern Standard Time)

Eastern Standard Time (EST) is observed during the winter months in the eastern part of North America. It covers 23 US states and parts of Canada including Ontario and Quebec. EST is the most populous time zone in the United States, home to major financial centers like New York City and global organizations headquartered in Washington D.C. During daylight saving time (March–November), clocks shift to Eastern Daylight Time (EDT, UTC-04:00). The time zone also covers parts of the Caribbean and Central America including Panama, Jamaica, and the Cayman Islands.

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 EST and Tehran

With a +8h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. Tehran opens at 9:00 AM IRST, which is 5:30 PM in EST, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

EST and Tehran have no shared working hours because of the +8h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.

EST is 8 hours 30 minutes ahead of Tehran (EST UTC-05:00 → IRST UTC+03:30). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

EST

☀ Currently in DST

Standard: UTC-05:00 · DST: UTC-04:00

Clocks fall back on Sun, Nov 1, 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:

⏳

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 EST and Tehran?

EST (EST, UTC-05:00) is 8 hours 30 minutes ahead of Tehran (IRST, UTC+03:30). The gap is currently +8h 30m.

How do I convert EST time to Tehran time?

Add +8h 30m to EST local time. For example, 9:00 AM in EST is 5:30 PM 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 +8h 30m offset from EST.

What is the best time to call Tehran from EST?

There is no shared working-hours window because of the +8h 30m gap. The closest option is 1:00 PM in EST, which is 9:30 PM in Tehran.

Which is ahead, EST or Tehran?

EST is 8 hours 30 minutes ahead of Tehran. When it is 12:00 PM in EST it is 8:30 PM in Tehran.

Do EST and Tehran use different time zones?

EST uses EST at UTC-05:00, while Tehran (Iran) uses IRST at UTC+03:30. The IANA identifiers are America/New_York and Asia/Tehran.

Does daylight saving time affect the EST–Tehran difference?

Neither zone observes daylight saving time, so the +8h 30m offset between EST and Tehran is fixed all year.

Which other cities share EST's time zone?

EST also covers New York City, Washington D.C., Miami, Toronto, Philadelphia, Atlanta, Boston, Montreal and 8 more.

Which countries use EST, EST's zone?

EST is used in United States (Eastern), Canada (Ontario, Quebec), Mexico (Quintana Roo), Panama, Jamaica, Cayman Islands, Haiti, Bahamas and 4 more.

Is there a day difference between EST and Tehran?

Not normally. The +8h 30m gap only pushes the date over for late-evening times.

What is the time difference between EST and Tehran?

Tehran is +8h 30m from EST.

What timezone is EST in?

EST 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 EST (Eastern Standard Time)?

EST is used in United States (Eastern), Canada (Ontario, Quebec), Mexico (Quintana Roo), Panama, Jamaica, Cayman Islands, and 6 more countries.

Does EST observe daylight saving time?

Yes, EST switches to EDT during summer months.

What are some interesting facts about EST?

EST is the most widely used time zone in the United States by population. The New York Stock Exchange (NYSE) and NASDAQ operate on Eastern Time, opening at 9:30 AM EST.