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).

Vietnam to GST

-3h

Vietnam

ICTSOURCE

UTC+07:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

GST

UTC+04:00

HH09

MM00

09:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Vietnam

GST

12:00 AM

9:00 PM-1

2:00 AM

11:00 PM-1

4:00 AM

1:00 AM

6:00 AM

3:00 AM

8:00 AM

5:00 AM

10:00 AM

7:00 AM

12:00 PM

9:00 AM

2:00 PM

11:00 AM

4:00 PM

1:00 PM

6:00 PM

3:00 PM

8:00 PM

5:00 PM

10:00 PM

7:00 PM

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

ICT and GST on the World Map

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

ICT Zone

→

GST Zone

Explore all world timezones interactively →

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

GST – Gulf Standard Time

UTC+04:00

Gulf Standard Time (GST) is used in the UAE, Oman, and other Gulf states, 4 hours ahead of UTC.

Countries in GST

UAEOmanGeorgiaAzerbaijanMauritius

Major Cities in GST

DubaiAbu DhabiMuscatBakuTbilisi

Key Facts about GST

•Dubai uses GST year-round with no daylight saving time.
•GST is 9 hours ahead of EST and 4 hours ahead of GMT.
•The Dubai Financial Market (DFM) operates on GST.

Daylight Saving:No – UTC+04:00 year-round

Learn more about GST on Wikipedia

Vietnam vs GST: Offsets, DST and Best Call Times

Vietnam runs on Indochina Time (ICT) at UTC+07:00. GST runs on Gulf Standard Time (GST) at UTC+04:00. That puts Vietnam 3 hours behind GST — a difference of -3h at the current offsets.

In practice, when it is 9:00 AM in Vietnam it is 6:00 AM in GST. Midnight in Vietnam is 9:00 PM in GST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Vietnam to GST time conversion table

Vietnam (ICT)	GST (GST)	Day
12:00 AM	9:00 PM	previous day
6:00 AM	3:00 AM	same day
7:00 AM	4:00 AM	same day
8:00 AM	5:00 AM	same day
9:00 AM	6:00 AM	same day
12:00 PM	9:00 AM	same day
3:00 PM	12:00 PM	same day
5:00 PM	2:00 PM	same day
6:00 PM	3:00 PM	same day
9:00 PM	6:00 PM	same day

Why people convert Vietnam to GST time

Scheduling a call from Vietnam to GST: a 10:00 AM start in Vietnam lands at 7:00 AM in GST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Vietnam and GST are inside the 9-to-5 working day between 12:00 PM and 5:00 PM ICT time (9:00 AM–2:00 PM GST). That is roughly 5 hours of usable overlap.
Booking travel or deliveries: tracking GST local time against Vietnam keeps pickup windows and arrival estimates honest across the -3h offset.

Always state the zone abbreviation, not just the hour. "3:00 PM ICT" is unambiguous; "3 PM" across a -3h gap is not.
Block 12:00 PM–5:00 PM ICT as the recurring meeting window if you work primarily from Vietnam and need GST colleagues present.

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.

About GST (Gulf Standard Time)

Gulf Standard Time (GST) is the time zone used in the United Arab Emirates, Oman, and other Gulf states. GST does not observe daylight saving time. Dubai and Abu Dhabi, major international business and tourism hubs, operate on GST.

Best time to call between Vietnam and GST

Both Vietnam and GST sit inside the 9 AM – 5 PM working day between 12:00 PM–5:00 PM ICT, which is 9:00 AM–2:00 PM GST. That gives roughly 5 hours of shared time — the safest window for a live call or meeting.

Business hours overlap

Vietnam and GST share 5 hours of working-hours overlap (12:00 PM–5:00 PM ICT), so scheduling a live meeting is straightforward.

Vietnam is 3 hours behind GST (ICT UTC+07:00 → GST UTC+04:00). The shared working window is 12:00 PM–5:00 PM ICT. 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 Vietnam and GST?

Vietnam (ICT, UTC+07:00) is 3 hours behind GST (GST, UTC+04:00). The gap is currently -3h.

How do I convert Vietnam time to GST time?

Add -3h to Vietnam local time. For example, 9:00 AM in Vietnam is 6:00 AM in GST.

What time is it in GST right now?

GST uses GST at UTC+04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -3h offset from Vietnam.