Iran to Colombo
+2hIran
IRSTSOURCEColombo
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 Colombo
WikipediaColombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
Sri Lanka Standard Time (SLST) uses UTC+5:30, same offset as India.
Iran to Colombo Time Difference – Complete Guide
Iran runs on Iran Standard Time (IRST) at UTC+03:30. Colombo runs on India Standard Time (IST) at UTC+05:30. That puts Iran 2 hours ahead of Colombo — a difference of +2h at the current offsets.
In practice, when it is 9:00 AM in Iran it is 11:00 AM in Colombo. Midnight in Iran is 2:00 AM in Colombo. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Iran to Colombo time conversion table
| Iran (IRST) | Colombo (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 Iran to Colombo time
- Scheduling a call from Iran to Colombo: a 10:00 AM start in Iran lands at 12:00 PM in Colombo, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Iran and Colombo 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.
- Keeping family and friends in sync: knowing that 8:00 PM in Iran is 10:00 PM in Colombo makes it easy to avoid calling at 3 AM.
- 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 Iran and need Colombo 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 Iran and Colombo
Both Iran and Colombo 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
Iran and Colombo share 6 hours of working-hours overlap (9:00 AM–3:00 PM IRST), so scheduling a live meeting is straightforward.
Iran is 2 hours ahead of Colombo (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 Iran and Colombo?
Iran (IRST, UTC+03:30) is 2 hours ahead of Colombo (IST, UTC+05:30). The gap is currently +2h.
How do I convert Iran time to Colombo time?
Add +2h to Iran local time. For example, 9:00 AM in Iran is 11:00 AM in Colombo.
What time is it in Colombo right now?
Colombo 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 Iran.
What is the best time to call Colombo from Iran?
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, Iran or Colombo?
Iran is 2 hours ahead of Colombo. When it is 12:00 PM in Iran it is 2:00 PM in Colombo.
Do Iran and Colombo use different time zones?
Iran (Iran) uses IRST at UTC+03:30, while Colombo (Sri Lanka) uses IST at UTC+05:30. The IANA identifiers are Asia/Tehran and Asia/Colombo.
Does daylight saving time affect the Iran–Colombo difference?
Neither zone observes daylight saving time, so the +2h offset between Iran and Colombo is fixed all year.
Which other cities share Iran's time zone?
IRST also covers Tehran, Isfahan, Mashhad, Tabriz, Shiraz, Karaj.
Which countries use IRST, Iran's zone?
IRST is used in Iran.
Is there a day difference between Iran and Colombo?
Not normally. The +2h gap only pushes the date over for late-evening times.
What is the time difference between Iran and Colombo?
Colombo is +2h from Iran.
What timezone is Iran in?
Iran operates on its local timezone.
What timezone is Colombo in?
Colombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
What are the business hours in Colombo?
Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.
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 Iran, what time is it in Colombo?
When it is 12:00 AM (midnight) in Iran (IRST), it is +2h later in Colombo (IST).
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