Does it handle Daylight Saving Time?

Yes, the tool automatically adjusts for Daylight Saving Time based on the specific date you select, ensuring accurate conversions year-round.

Can I add multiple cities?

Yes, you can add as many cities as you need to the dashboard to compare times across your entire global network simultaneously.

Tehran to Sri Lanka

+2h

Tehran

IRSTSOURCE

Iran · UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Sri Lanka

IST

UTC+05:30

HH02

MM00

14:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Tehran

Sri Lanka

12:00 AM

2:00 AM

4:00 AM

6:00 AM

8:00 AM

10:00 AM

12:00 PM

2:00 PM

4:00 PM

6:00 PM

8:00 PM

10:00 PM

12:00 AM+1

Green 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 Zone

→

IST 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

IST – India Standard Time

UTC+05:30

India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.

Countries in IST

IndiaSri Lanka

Major Cities in IST

MumbaiDelhiBangaloreKolkataChennaiHyderabadPuneAhmedabadColomboJaipurLucknowSurat

Key Facts about IST

•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.

Daylight Saving:No – UTC+05:30 year-round

Learn more about IST on Wikipedia

About Tehran

Wikipedia

Tehran operates on Iran Standard Time (IRST), UTC+3:30. Iran's unique half-hour offset makes Tehran time distinctive for regional business coordination.

Population:9.4 million

Metro:16.8 million

Business Hours:8:00 AM - 4:00 PM IRST

Currency:IRR (﷼)

Stock Exchange:TSE (Tehran Stock Exchange)

Key Landmarks

Azadi TowerGolestan PalaceGrand BazaarMilad TowerTabiat Bridge

Did You Know?

Iran Standard Time (IRST) is one of few timezones with a 30-minute offset (UTC+3:30).

Learn more about IRST timezone →

Tehran vs Sri Lanka: Offsets, DST and Best Call Times

Tehran runs on Iran Standard Time (IRST) at UTC+03:30. Sri Lanka runs on India Standard Time (IST) at UTC+05:30. That puts Tehran 2 hours ahead of Sri Lanka — a difference of +2h at the current offsets.

In practice, when it is 9:00 AM in Tehran it is 11:00 AM in Sri Lanka. Midnight in Tehran is 2:00 AM in Sri Lanka. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Tehran to Sri Lanka time conversion table

Tehran (IRST)	Sri Lanka (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 Sri Lanka time

Scheduling a call from Tehran to Sri Lanka: a 10:00 AM start in Tehran lands at 12:00 PM in Sri Lanka, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Tehran and Sri Lanka 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.
Coordinating a Tehran-based team with Sri Lanka 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 +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 Sri Lanka 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 Sri Lanka

Both Tehran and Sri Lanka 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 Sri Lanka 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 Sri Lanka (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:

⏳

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 Tehran and Sri Lanka?

Tehran (IRST, UTC+03:30) is 2 hours ahead of Sri Lanka (IST, UTC+05:30). The gap is currently +2h.

How do I convert Tehran time to Sri Lanka time?

Add +2h to Tehran local time. For example, 9:00 AM in Tehran is 11:00 AM in Sri Lanka.

What time is it in Sri Lanka right now?

Sri Lanka 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 Sri Lanka 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 Sri Lanka?

Tehran is 2 hours ahead of Sri Lanka. When it is 12:00 PM in Tehran it is 2:00 PM in Sri Lanka.

Do Tehran and Sri Lanka use different time zones?

Tehran (Iran) uses IRST at UTC+03:30, while Sri Lanka (Sri Lanka) uses IST at UTC+05:30. The IANA identifiers are Asia/Tehran and Asia/Colombo.

Does daylight saving time affect the Tehran–Sri Lanka difference?

Neither zone observes daylight saving time, so the +2h offset between Tehran and Sri Lanka 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 Sri Lanka?

Not normally. The +2h gap only pushes the date over for late-evening times.

What is the time difference between Tehran and Sri Lanka?

Sri Lanka 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.