IRST to EST
-8h 30mIRST
IRSTSOURCEEST
ESTGreen rows indicate typical business hours (9 AM - 5 PM)
IRST and EST on the World Map
The map below highlights the IRST (Iran Standard Time) and EST (Eastern Standard Time) timezone regions across the globe.
IRST – Iran Standard Time
UTC+03:30Iran Standard Time (IRST) is the time zone for Iran, 3 hours and 30 minutes ahead of UTC.
- •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.
EST – Eastern Standard Time
UTC-05:00Eastern Standard Time (EST) is the time zone for the eastern United States and Canada, 5 hours behind UTC.
- •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.
Time Conversion Guide: IRST to EST
IRST runs on Iran Standard Time (IRST) at UTC+03:30. EST runs on Eastern Standard Time (EST) at UTC-05:00. That puts IRST 8 hours 30 minutes behind EST — a difference of -8h 30m at the current offsets.
In practice, when it is 9:00 AM in IRST it is 12:30 AM in EST. Midnight in IRST is 3:30 PM in EST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
IRST to EST time conversion table
| IRST (IRST) | EST (EST) | Day |
|---|---|---|
| 12:00 AM | 3:30 PM | previous day |
| 6:00 AM | 9:30 PM | previous day |
| 7:00 AM | 10:30 PM | previous day |
| 8:00 AM | 11:30 PM | previous day |
| 9:00 AM | 12:30 AM | same day |
| 12:00 PM | 3:30 AM | same day |
| 3:00 PM | 6:30 AM | same day |
| 5:00 PM | 8:30 AM | same day |
| 6:00 PM | 9:30 AM | same day |
| 9:00 PM | 12:30 PM | same day |
Why people convert IRST to EST time
- Scheduling a call from IRST to EST: a 10:00 AM start in IRST lands at 1:30 AM in EST, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -8h 30m gap: IRST and EST 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 EST is 12:30 AM in IRST.
- Coordinating a IRST-based team with EST 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 -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 IRST takes the early slot, the next week EST does.
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 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.
Best time to call between IRST and EST
With a -8h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. EST opens at 9:00 AM EST, which is 12:30 AM in IRST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
IRST and EST have no shared working hours because of the -8h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.
IRST is 8 hours 30 minutes behind EST (IRST UTC+03:30 → EST UTC-05:00). 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
IRST
Does not observe DST
EST
☀ 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:
Frequently Asked Questions
What is the time difference between IRST and EST?
IRST (IRST, UTC+03:30) is 8 hours 30 minutes behind EST (EST, UTC-05:00). The gap is currently -8h 30m.
How do I convert IRST time to EST time?
Add -8h 30m to IRST local time. For example, 9:00 AM in IRST is 12:30 AM in EST.
What time is it in EST right now?
EST uses EST at UTC-05:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -8h 30m offset from IRST.
What is the best time to call EST from IRST?
There is no shared working-hours window because of the -8h 30m gap. The closest option is 1:00 PM in IRST, which is 4:30 AM in EST.
Which is behind, IRST or EST?
IRST is 8 hours 30 minutes behind EST. When it is 12:00 PM in IRST it is 3:30 AM in EST.
Does daylight saving time affect the IRST–EST difference?
Neither zone observes daylight saving time, so the -8h 30m offset between IRST and EST 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 EST?
Not normally. The -8h 30m gap only pushes the date over the previous day.
What is the time difference between IRST and EST?
EST is -8h 30m from IRST.
What timezone is IRST in?
IRST operates on its local timezone.
What timezone is EST in?
EST 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 EST timezone?
Major cities in the EST timezone include New York City, Washington D.C., Miami, Toronto, Philadelphia, Atlanta, Boston, Montreal.
What is the UTC offset for EST?
Eastern Standard Time (EST) is at UTC-05:00. During daylight saving time, it shifts to EDT.
What should I know about the EST timezone?
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.
When is it midnight in IRST, what time is it in EST?
When it is 12:00 AM (midnight) in IRST (IRST), it is -8h 30m later in EST (EST).
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See every conversion from IRST →·See every conversion from EST →