Tehran to IST
+2hTehran
IRSTSOURCEIST
ISTGreen rows indicate typical business hours (9 AM - 5 PM)
IRST and IST on the World Map
The map below highlights the IRST (Iran Standard Time) and IST (India 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.
IST – India Standard Time
UTC+05:30India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.
- •India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT.
- •India uses a single time zone despite spanning 30° of longitude.
- •IST is one of only a handful of time zones with a 30-minute offset.
- •IST is the most populous single time zone in the world with over 1.4 billion people.
- •The Bombay Stock Exchange (BSE) and National Stock Exchange (NSE) operate on IST.
About Tehran
WikipediaTehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.
Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).
Understanding the +2h Gap: Tehran vs IST
Tehran runs on Iran Standard Time (IRST) at UTC+03:30. IST runs on India Standard Time (IST) at UTC+05:30. That puts Tehran 2 hours ahead of IST — a difference of +2h at the current offsets.
In practice, when it is 9:00 AM in Tehran it is 11:00 AM in IST. Midnight in Tehran is 2:00 AM in IST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Tehran to IST time conversion table
| Tehran (IRST) | IST (IST) | Day |
|---|---|---|
| 12:00 AM | 2:00 AM | same day |
| 6:00 AM | 8:00 AM | same day |
| 7:00 AM | 9:00 AM | same day |
| 8:00 AM | 10:00 AM | same day |
| 9:00 AM | 11:00 AM | same day |
| 12:00 PM | 2:00 PM | same day |
| 3:00 PM | 5:00 PM | same day |
| 5:00 PM | 7:00 PM | same day |
| 6:00 PM | 8:00 PM | same day |
| 9:00 PM | 11:00 PM | same day |
Why people convert Tehran to IST time
- Scheduling a call from Tehran to IST: a 10:00 AM start in Tehran lands at 12:00 PM in IST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Tehran and IST are inside the 9-to-5 working day between 9:00 AM and 3:00 PM IRST time (11:00 AM–5:00 PM IST). That is roughly 6 hours of usable overlap.
- Watching a live event or market open: Tehran viewers need 11:00 AM in IST to catch a 9:00 AM start there, and 10:00 PM if the event is anchored to Tehran.
- Always state the zone abbreviation, not just the hour. "3:00 PM IRST" is unambiguous; "3 PM" across a +2h gap is not.
- Block 9:00 AM–3:00 PM IRST as the recurring meeting window if you work primarily from Tehran and need IST 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 IST (India Standard Time)
India Standard Time (IST) is the time observed throughout India and Sri Lanka. It is based on the 82.5°E meridian, passing through Mirzapur in Uttar Pradesh. India uses a single time zone despite spanning roughly 30° of longitude, which has been debated. IST does not observe daylight saving time. India is the world's most populous country, making IST one of the most-used time zones globally. The IT outsourcing industry and call centers operate primarily on IST, making the EST-to-IST conversion one of the most searched timezone conversions.
Best time to call between Tehran and IST
Both Tehran and IST sit inside the 9 AM – 5 PM working day between 9:00 AM–3:00 PM IRST, which is 11:00 AM–5:00 PM IST. That gives roughly 6 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
Tehran and IST share 6 hours of working-hours overlap (9:00 AM–3:00 PM IRST), so scheduling a live meeting is straightforward.
Tehran is 2 hours ahead of IST (IRST UTC+03:30 → IST UTC+05:30). The shared working window is 9:00 AM–3:00 PM IRST. 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:
Frequently Asked Questions
What is the time difference between Tehran and IST?
Tehran (IRST, UTC+03:30) is 2 hours ahead of IST (IST, UTC+05:30). The gap is currently +2h.
How do I convert Tehran time to IST time?
Add +2h to Tehran local time. For example, 9:00 AM in Tehran is 11:00 AM in IST.
What time is it in IST right now?
IST uses IST at UTC+05:30. Use the live converter at the top of this page — it updates in real time and already accounts for the +2h offset from Tehran.
What is the best time to call IST from Tehran?
Call between 9:00 AM and 3:00 PM IRST — that maps to 11:00 AM–5:00 PM IST and keeps both parties inside the working day.
Which is ahead, Tehran or IST?
Tehran is 2 hours ahead of IST. When it is 12:00 PM in Tehran it is 2:00 PM in IST.
Do Tehran and IST use different time zones?
Tehran (Iran) uses IRST at UTC+03:30, while IST uses IST at UTC+05:30. The IANA identifiers are Asia/Tehran and Asia/Kolkata.
Does daylight saving time affect the Tehran–IST difference?
Neither zone observes daylight saving time, so the +2h offset between Tehran and IST is fixed all year.
Which other cities share Tehran's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, Tehran's zone?
IRST is used in Iran.
Is there a day difference between Tehran and IST?
Not normally. The +2h gap only pushes the date over for late-evening times.
What is the time difference between Tehran and IST?
IST is +2h from Tehran.
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 timezone is IST in?
IST operates on its local timezone.
What are the business hours in Tehran?
Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.
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 IST timezone?
Major cities in the IST timezone include Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad.
What is the UTC offset for IST?
India Standard Time (IST) is at UTC+05:30.
What should I know about the IST timezone?
India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT. India uses a single time zone despite spanning 30° of longitude.
When is it midnight in Tehran, what time is it in IST?
When it is 12:00 AM (midnight) in Tehran (IRST), it is +2h later in IST (IST).
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