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).

IST to ICT

+1h 30m

IST

ISTSOURCE

UTC+05:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

ICT

UTC+07:00

HH01

MM30

13:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IST

ICT

12:00 AM

1:30 AM

2:00 AM

3:30 AM

4:00 AM

5:30 AM

6:00 AM

7:30 AM

8:00 AM

9:30 AM

10:00 AM

11:30 AM

12:00 PM

1:30 PM

2:00 PM

3:30 PM

4:00 PM

5:30 PM

6:00 PM

7:30 PM

8:00 PM

9:30 PM

10:00 PM

11:30 PM

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

IST and ICT on the World Map

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

IST Zone

→

ICT Zone

Explore all world timezones interactively →

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

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

IST vs ICT: Offsets, DST and Best Call Times

IST runs on India Standard Time (IST) at UTC+05:30. ICT runs on Indochina Time (ICT) at UTC+07:00. That puts IST 1 hour 30 minutes ahead of ICT — a difference of +1h 30m at the current offsets.

In practice, when it is 9:00 AM in IST it is 10:30 AM in ICT. Midnight in IST is 1:30 AM in ICT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IST to ICT time conversion table

IST (IST)	ICT (ICT)	Day
12:00 AM	1:30 AM	same day
6:00 AM	7:30 AM	same day
7:00 AM	8:30 AM	same day
8:00 AM	9:30 AM	same day
9:00 AM	10:30 AM	same day
12:00 PM	1:30 PM	same day
3:00 PM	4:30 PM	same day
5:00 PM	6:30 PM	same day
6:00 PM	7:30 PM	same day
9:00 PM	10:30 PM	same day

Why people convert IST to ICT time

Scheduling a call from IST to ICT: a 10:00 AM start in IST lands at 11:30 AM in ICT, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both IST and ICT are inside the 9-to-5 working day between 9:00 AM and 3:30 PM IST time (10:30 AM–5:00 PM ICT). That is roughly 6 hours 30 minutes of usable overlap.
Coordinating a IST-based team with ICT 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 IST" is unambiguous; "3 PM" across a +1h 30m gap is not.
Block 9:00 AM–3:30 PM IST as the recurring meeting window if you work primarily from IST and need ICT colleagues present.

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.

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 IST and ICT

Both IST and ICT sit inside the 9 AM – 5 PM working day between 9:00 AM–3:30 PM IST, which is 10:30 AM–5:00 PM ICT. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

IST and ICT share 6 hours of working-hours overlap (9:00 AM–3:30 PM IST), so scheduling a live meeting is straightforward.

IST is 1 hour 30 minutes ahead of ICT (IST UTC+05:30 → ICT UTC+07:00). The shared working window is 9:00 AM–3:30 PM IST. 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 IST and ICT?

IST (IST, UTC+05:30) is 1 hour 30 minutes ahead of ICT (ICT, UTC+07:00). The gap is currently +1h 30m.

How do I convert IST time to ICT time?

Add +1h 30m to IST local time. For example, 9:00 AM in IST is 10:30 AM in ICT.

What time is it in ICT right now?

ICT 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 +1h 30m offset from IST.