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).

GST to JST

+5h

GST

GSTSOURCE

UTC+04:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

JST

UTC+09:00

HH05

MM00

17:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

GST

JST

12:00 AM

5:00 AM

2:00 AM

7:00 AM

4:00 AM

9:00 AM

6:00 AM

11:00 AM

8:00 AM

1:00 PM

10:00 AM

3:00 PM

12:00 PM

5:00 PM

2:00 PM

7:00 PM

4:00 PM

9:00 PM

6:00 PM

11:00 PM

8:00 PM

1:00 AM+1

10:00 PM

3:00 AM+1

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

GST and JST on the World Map

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

GST Zone

→

JST Zone

Explore all world timezones interactively →

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

JST – Japan Standard Time

UTC+09:00

Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.

Countries in JST

Japan

Major Cities in JST

TokyoOsakaYokohamaNagoyaSapporoKyotoKobeFukuokaHiroshima

Key Facts about JST

•Japan does not observe daylight saving time.
•Tokyo is the most populous metropolitan area in the world.
•The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
•JST is 14 hours ahead of EST and 9 hours ahead of GMT.

Daylight Saving:No – UTC+09:00 year-round

Learn more about JST on Wikipedia

GST to JST Time Difference – Complete Guide

GST runs on Gulf Standard Time (GST) at UTC+04:00. JST runs on Japan Standard Time (JST) at UTC+09:00. That puts GST 5 hours ahead of JST — a difference of +5h at the current offsets.

In practice, when it is 9:00 AM in GST it is 2:00 PM in JST. Midnight in GST is 5:00 AM in JST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

GST to JST time conversion table

GST (GST)	JST (JST)	Day
12:00 AM	5:00 AM	same day
6:00 AM	11:00 AM	same day
7:00 AM	12:00 PM	same day
8:00 AM	1:00 PM	same day
9:00 AM	2:00 PM	same day
12:00 PM	5:00 PM	same day
3:00 PM	8:00 PM	same day
5:00 PM	10:00 PM	same day
6:00 PM	11:00 PM	same day
9:00 PM	2:00 AM	next day

Why people convert GST to JST time

Scheduling a call from GST to JST: a 10:00 AM start in GST lands at 3:00 PM in JST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both GST and JST are inside the 9-to-5 working day between 9:00 AM and 12:00 PM GST time (2:00 PM–5:00 PM JST). That is roughly 3 hours of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in GST is 1:00 AM in JST makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM GST" is unambiguous; "3 PM" across a +5h gap is not.
Block 9:00 AM–12:00 PM GST as the recurring meeting window if you work primarily from GST and need JST colleagues present.

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.

About JST (Japan Standard Time)

Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.

Best time to call between GST and JST

Both GST and JST sit inside the 9 AM – 5 PM working day between 9:00 AM–12:00 PM GST, which is 2:00 PM–5:00 PM JST. That gives roughly 3 hours of shared time — the safest window for a live call or meeting.

Business hours overlap

GST and JST overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.

GST is 5 hours ahead of JST (GST UTC+04:00 → JST UTC+09:00). The shared working window is 9:00 AM–12:00 PM GST. Remember to re-check around daylight-saving transitions.