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).

IRST to EDT

-7h 30m

IRST

IRSTSOURCE

UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

EDT

UTC-04:00☀ DST active

HH04

MM30

04:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IRST

EDT

12:00 AM

4:30 PM-1

2:00 AM

6:30 PM-1

4:00 AM

8:30 PM-1

6:00 AM

10:30 PM-1

8:00 AM

12:30 AM

10:00 AM

2:30 AM

12:00 PM

4:30 AM

2:00 PM

6:30 AM

4:00 PM

8:30 AM

6:00 PM

10:30 AM

8:00 PM

12:30 PM

10:00 PM

2:30 PM

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

IRST and EDT on the World Map

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

IRST Zone

→

EDT 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

EDT – Eastern Daylight Time

UTC-04:00

Eastern Daylight Time (EDT) is the daylight saving time observed in the Eastern Time Zone, 4 hours behind UTC.

Countries in EDT

United States (Eastern)Canada (Ontario, Quebec)BahamasHaitiTurks and Caicos

Major Cities in EDT

New York CityWashington D.C.TorontoMiamiPhiladelphiaAtlantaBostonMontreal

Key Facts about EDT

•EDT is observed from the second Sunday of March to the first Sunday of November.
•During EDT, the US East Coast is only 4 hours behind London (instead of 5).
•Not all EST locations switch to EDT – Panama and Jamaica stay on EST year-round.

Daylight Saving:Yes – switches to EST

Learn more about EDT on Wikipedia

Comparing Time Zones: IRST and EDT

IRST runs on Iran Standard Time (IRST) at UTC+03:30. EDT runs on Eastern Daylight Time (EDT) at UTC-04:00. That puts IRST 7 hours 30 minutes behind EDT — a difference of -7h 30m at the current offsets.

In practice, when it is 9:00 AM in IRST it is 1:30 AM in EDT. Midnight in IRST is 4:30 PM in EDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IRST to EDT time conversion table

IRST (IRST)	EDT (EDT)	Day
12:00 AM	4:30 PM	previous day
6:00 AM	10:30 PM	previous day
7:00 AM	11:30 PM	previous day
8:00 AM	12:30 AM	same day
9:00 AM	1:30 AM	same day
12:00 PM	4:30 AM	same day
3:00 PM	7:30 AM	same day
5:00 PM	9:30 AM	same day
6:00 PM	10:30 AM	same day
9:00 PM	1:30 PM	same day

Why people convert IRST to EDT time

Scheduling a call from IRST to EDT: a 10:00 AM start in IRST lands at 2:30 AM in EDT, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IRST and EDT are inside the 9-to-5 working day between 4:30 PM and 5:00 PM IRST time (9:00 AM–9:30 AM EDT). That is roughly 0 hours 30 minutes of usable overlap.
Coordinating a IRST-based team with EDT 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 IRST" is unambiguous; "3 PM" across a -7h 30m gap is not.
Block 4:30 PM–5:00 PM IRST as the recurring meeting window if you work primarily from IRST and need EDT 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 EDT (Eastern Daylight Time)

Eastern Daylight Time (EDT) is used during the summer months (second Sunday of March to the first Sunday of November) in the Eastern Time Zone. During EDT, clocks are advanced by one hour to take advantage of longer daylight hours. Not all locations in the Eastern Time Zone observe DST – Panama, Jamaica, and most of the Caribbean remain on EST year-round.

Best time to call between IRST and EDT

Both IRST and EDT sit inside the 9 AM – 5 PM working day between 4:30 PM–5:00 PM IRST, which is 9:00 AM–9:30 AM EDT. That gives roughly 0 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IRST and EDT overlap for only 30 minutes (4:30 PM–5:00 PM IRST), so meetings have to be booked precisely.

IRST is 7 hours 30 minutes behind EDT (IRST UTC+03:30 → EDT UTC-04:00). The shared working window is 4:30 PM–5:00 PM IRST. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

IRST

Does not observe DST

EDT

☀ Currently in DST

Standard: UTC-05:00 · DST: UTC-04:00

Clocks fall back on Sun, Nov 1, 2026

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 EDT?

IRST (IRST, UTC+03:30) is 7 hours 30 minutes behind EDT (EDT, UTC-04:00). The gap is currently -7h 30m.

How do I convert IRST time to EDT time?

Add -7h 30m to IRST local time. For example, 9:00 AM in IRST is 1:30 AM in EDT.

What time is it in EDT right now?

EDT uses EDT at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -7h 30m offset from IRST.

What is the best time to call EDT from IRST?

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

Which is behind, IRST or EDT?

IRST is 7 hours 30 minutes behind EDT. When it is 12:00 PM in IRST it is 4:30 AM in EDT.

Does daylight saving time affect the IRST–EDT difference?

Neither zone observes daylight saving time, so the -7h 30m offset between IRST and EDT is fixed all year.

Which other cities share IRST's time zone?

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

Which countries use IRST, IRST's zone?

IRST is used in Iran.

Is there a day difference between IRST and EDT?

Not normally. The -7h 30m gap only pushes the date over the previous day.

What is the time difference between IRST and EDT?

EDT is -7h 30m from IRST.

What timezone is IRST in?

IRST operates on its local timezone.

What timezone is EDT in?

EDT operates on its local timezone.

Which countries use IRST (Iran Standard Time)?

IRST is used in Iran.

Does IRST observe daylight saving time?

Yes, IRST switches to IRDT during summer months.

What are some interesting 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).

Which cities are in the EDT timezone?

Major cities in the EDT timezone include New York City, Washington D.C., Toronto, Miami, Philadelphia, Atlanta, Boston, Montreal.

What is the UTC offset for EDT?

Eastern Daylight Time (EDT) is at UTC-04:00. During daylight saving time, it shifts to EST.

What should I know about the EDT timezone?

EDT is observed from the second Sunday of March to the first Sunday of November. During EDT, the US East Coast is only 4 hours behind London (instead of 5).