What is the time difference between IRST and EST?

Eastern Standard Time (EST) is 7 hours and 30 minutes behind Iran Standard Time (IRST). IRST uses a UTC offset of UTC+3:30, while EST uses UTC-4. For example, when it's 9:00 AM in IRST, it's 1:30 AM in EST. Note that this difference may shift by one hour during daylight saving time transitions if EST observes DST. Use the conversion table above to see the exact time for each hour of the day.

How do I convert IRST to EST?

To convert IRST to EST, subtract 7 hours and 30 minutes from the IRST time. For example, 9:00 AM IRST is 1:30 AM EST, and 5:00 PM IRST is 9:30 AM EST. Keep in mind that during daylight saving time transitions, the offset between these timezones may temporarily change by one hour. You can also use the interactive converter above for quick, accurate results.

What time is it in EST when it's noon in IRST?

When it's 12:00 PM (noon) in IRST, it's 4:30 AM in EST. This is because EST is 7 hours and 30 minutes behind IRST. Similarly, when it's 6:00 PM in IRST, it's 10:30 AM in EST. During daylight saving time transitions, these times may shift by one hour, so always verify the current offset. The color-coded conversion table above shows every hour mapped between both timezones.

How many hours behind is EST from IRST?

EST is 7 hours and 30 minutes behind IRST. This means when it's 9:00 AM in IRST, it's 1:30 AM in EST, and when it's midnight in IRST, it's 4:30 PM in EST. The exact difference can vary by one hour during daylight saving time transitions. The conversion table above provides a complete hour-by-hour mapping.

Is EST ahead or behind IRST?

EST is behind IRST by 7 hours and 30 minutes. Clocks in EST show an earlier time than IRST, meaning the day starts later in EST relative to IRST. For example, when it's noon in IRST, it's still 4:30 AM in EST. This gap may change by one hour during DST transitions.

Does IRST observe daylight saving time?

No, Iran Standard Time does not observe daylight saving time. The UTC offset of UTC+3:30 remains the same year-round, which simplifies time conversions. Regions using IRST keep their clocks unchanged regardless of the season.

Does EST observe daylight saving time?

Yes, Eastern Standard Time observes daylight saving time. During DST, the abbreviation changes to EDT and clocks move forward by one hour, typically in spring. Clocks then fall back in autumn, returning to standard EST time. This means the UTC offset for EST shifts between two values depending on the season. Check our DST change calendar for exact transition dates that may affect your IRST to EST conversions.

What is the best time to call from IRST to EST?

The best time for a call between IRST and EST is during overlapping business hours (9 AM – 5 PM) in both timezones. To reach someone in EST during their work day, call between 4:30 PM and 12:30 AM your IRST time. Avoid calling too early or late, as the 7 hours and 30 minutes difference means your evening could be their early morning. Check the color-coded conversion table above — green hours indicate business hours in both zones, making it easy to find the ideal time.

When does daylight saving time change in EST?

Daylight saving time transitions vary by year and region. Eastern Standard Time observes DST, which typically shifts clocks forward by one hour in spring ("spring forward") and back in fall ("fall back"). During these transition periods, the time difference between IRST and EST may temporarily change by one hour, which can cause confusion for scheduled meetings or calls. It's important to double-check your conversions around transition dates, especially if the two timezones switch on different dates. Check our DST change calendar for exact transition dates in the current year.

Do IRST and EST ever have the same time?

No, IRST and EST never show the same time because their base UTC offsets are different. However, because EST observes daylight saving time and IRST does not, the time difference between them changes by one hour during DST transitions. This means the gap narrows or widens depending on the season, but the two clocks never align. Always verify the current offset around DST transition dates to avoid scheduling errors.

IRST to EST Converter

Convert Iran Standard Time to Eastern Standard Time. See the hour-by-hour conversion table below.

Timezone Details

Tehran

12:46 AM

Friday, April 3, 2026

Tehran (UTC+03:30)

Eastern Standard Time

5:16 PM

Thursday, April 2, 2026

EDT (UTC-04:00)

Difference: -7h 30m

EDT DST: Yes (EDT)

24-Hour Overview

Tehran — 24-hour overview

12a12a

3a3a

6a6a

9a9a

10a

11a

12p12p

3p3p

6p6p

9p9p

10p

11p

NightMorningBusinessEvening

EDT — 24-hour overview

4p4p

7p7p

10p10p

11p

12a

1a1a

4a4a

7a7a

10a10a

11a

12p

1p1p

NightMorningBusinessEvening

Frequently Asked Questions

Related Conversions

EST to IRST EST to PST PST to EST EST to GMT GMT to EST EST to IST IST to EST EST to CET CET to EST

Cities in These Timezones

IRST Cities

Tehran

EST Cities

New York Philadelphia Washington D.C.Boston Atlanta

More Tools

Compare IRST & EST Plan a Meeting (IRST & EST)See on Map

Learn More

How Time Zones Work Understanding DST Timezone Abbreviations

External Resources

Eastern Standard Time on Wikipedia IANA Time Zone Database