Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

Tehran to Bangkok

+3h 30m

Tehran

IRSTSOURCE

Iran · UTC+03:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Bangkok

ICT

Thailand · UTC+07:00

HH03

MM30

15:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Tehran

Bangkok

12:00 AM

3:30 AM

2:00 AM

5:30 AM

4:00 AM

7:30 AM

6:00 AM

9:30 AM

8:00 AM

11:30 AM

10:00 AM

1:30 PM

12:00 PM

3:30 PM

2:00 PM

5:30 PM

4:00 PM

7:30 PM

6:00 PM

9:30 PM

8:00 PM

11:30 PM

10:00 PM

1:30 AM+1

Green rows indicate typical business hours (9 AM - 5 PM)

IRST and ICT on the World Map

The map below highlights the IRST (Iran Standard Time) and ICT (Indochina Time) timezone regions across the globe.

IRST Zone

→

ICT 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

ICT – Indochina Time

UTC+07:00

Indochina Time (ICT) is the time zone for Vietnam, Thailand, Laos, and Cambodia, 7 hours ahead of UTC.

Countries in ICT

ThailandVietnamCambodiaLaosIndonesia (WIB)

Major Cities in ICT

BangkokHo Chi Minh CityHanoiJakartaPhnom PenhVientiane

Key Facts about ICT

•Bangkok is one of the most visited cities in the world.
•ICT is 12 hours ahead of EST.
•Thailand, Vietnam, and Cambodia all share ICT.

Daylight Saving:No – UTC+07:00 year-round

Learn more about ICT 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 →

About Bangkok

Wikipedia

Bangkok operates on Indochina Time (ICT), UTC+7. As Southeast Asia's largest economy hub, Bangkok bridges East Asian and South Asian business hours.

Population:8.3 million

Metro:14.6 million

Business Hours:8:30 AM - 5:30 PM ICT

Currency:THB (฿)

Stock Exchange:SET (Stock Exchange of Thailand)

Key Landmarks

Grand PalaceWat ArunWat PhoChatuchak MarketKhao San Road

Did You Know?

Bangkok is one of the world's most visited cities, with over 22 million visitors annually.

Learn more about ICT timezone →

Comparing Time Zones: Tehran and Bangkok

Tehran runs on Iran Standard Time (IRST) at UTC+03:30. Bangkok runs on Indochina Time (ICT) at UTC+07:00. That puts Tehran 3 hours 30 minutes ahead of Bangkok — a difference of +3h 30m at the current offsets.

In practice, when it is 9:00 AM in Tehran it is 12:30 PM in Bangkok. Midnight in Tehran is 3:30 AM in Bangkok. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Tehran to Bangkok time conversion table

Tehran (IRST)	Bangkok (ICT)	Day
12:00 AM	3:30 AM	same day
6:00 AM	9:30 AM	same day
7:00 AM	10:30 AM	same day
8:00 AM	11:30 AM	same day
9:00 AM	12:30 PM	same day
12:00 PM	3:30 PM	same day
3:00 PM	6:30 PM	same day
5:00 PM	8:30 PM	same day
6:00 PM	9:30 PM	same day
9:00 PM	12:30 AM	next day

Why people convert Tehran to Bangkok time

Scheduling a call from Tehran to Bangkok: a 10:00 AM start in Tehran lands at 1:30 PM in Bangkok, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Tehran and Bangkok are inside the 9-to-5 working day between 9:00 AM and 1:30 PM IRST time (12:30 PM–5:00 PM ICT). That is roughly 4 hours 30 minutes of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in Tehran is 11:30 PM in Bangkok 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 +3h 30m gap is not.
Block 9:00 AM–1:30 PM IRST as the recurring meeting window if you work primarily from Tehran and need Bangkok 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 ICT (Indochina Time)

Indochina Time (ICT) is used across Southeast Asia including Vietnam, Thailand, Laos, and Cambodia. Indonesia (Western time, WIB) also uses UTC+07:00. ICT does not observe daylight saving time.

Best time to call between Tehran and Bangkok

Both Tehran and Bangkok sit inside the 9 AM – 5 PM working day between 9:00 AM–1:30 PM IRST, which is 12:30 PM–5:00 PM ICT. That gives roughly 4 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

Tehran and Bangkok overlap for about 4 hours during the working day — enough for meetings if you avoid the edges of the window.

Tehran is 3 hours 30 minutes ahead of Bangkok (IRST UTC+03:30 → ICT UTC+07:00). The shared working window is 9:00 AM–1:30 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 Bangkok?

Tehran (IRST, UTC+03:30) is 3 hours 30 minutes ahead of Bangkok (ICT, UTC+07:00). The gap is currently +3h 30m.

How do I convert Tehran time to Bangkok time?

Add +3h 30m to Tehran local time. For example, 9:00 AM in Tehran is 12:30 PM in Bangkok.

What time is it in Bangkok right now?

Bangkok uses ICT at UTC+07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +3h 30m offset from Tehran.

What is the best time to call Bangkok from Tehran?

Call between 9:00 AM and 1:30 PM IRST — that maps to 12:30 PM–5:00 PM ICT and keeps both parties inside the working day.

Which is ahead, Tehran or Bangkok?

Tehran is 3 hours 30 minutes ahead of Bangkok. When it is 12:00 PM in Tehran it is 3:30 PM in Bangkok.

Do Tehran and Bangkok use different time zones?

Tehran (Iran) uses IRST at UTC+03:30, while Bangkok (Thailand) uses ICT at UTC+07:00. The IANA identifiers are Asia/Tehran and Asia/Bangkok.

Does daylight saving time affect the Tehran–Bangkok difference?

Neither zone observes daylight saving time, so the +3h 30m offset between Tehran and Bangkok 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 Bangkok?

Not normally. The +3h 30m gap only pushes the date over for late-evening times.

What is the time difference between Tehran and Bangkok?

Bangkok is +3h 30m 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 Bangkok in?

Bangkok operates on Indochina Time (ICT), UTC+7. As Southeast Asia's largest economy hub, Bangkok bridges East Asian and South Asian business hours.

What are the business hours in Tehran?

Standard business hours in Tehran are 8:00 AM - 4:00 PM IRST.

What are the business hours in Bangkok?

Standard business hours in Bangkok are 8:30 AM - 5:30 PM ICT.

What is the best time to schedule a call between Tehran and Bangkok?

The best overlap for a call is when both cities are in business hours. Tehran works 8:00 AM - 4:00 PM IRST and Bangkok works 8:30 AM - 5:30 PM ICT (+3h 30m difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Tehran and Bangkok?

Tehran uses IRR (﷼) while Bangkok uses THB (฿). Check current exchange rates when planning travel or business between these cities.

How do Tehran and Bangkok compare in size?

Tehran has a population of approximately 9.4 million (metro: 16.8 million), while Bangkok has approximately 8.3 million (metro: 14.6 million).

What are the major landmarks in Tehran and Bangkok?

Tehran is known for Azadi Tower, Golestan Palace, Grand Bazaar. Bangkok is famous for Grand Palace, Wat Arun, Wat Pho.

Do Tehran and Bangkok have stock exchanges?

Yes. Tehran has the TSE (Tehran Stock Exchange) and Bangkok has the SET (Stock Exchange of Thailand). The +3h 30m time difference affects trading hour overlaps between these exchanges.