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).

Sri Lanka to GST

-1h 30m

Sri Lanka

ISTSOURCE

UTC+05:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

GST

UTC+04:00

HH10

MM30

10:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Sri Lanka

GST

12:00 AM

10:30 PM-1

2:00 AM

12:30 AM

4:00 AM

2:30 AM

6:00 AM

4:30 AM

8:00 AM

6:30 AM

10:00 AM

8:30 AM

12:00 PM

10:30 AM

2:00 PM

12:30 PM

4:00 PM

2:30 PM

6:00 PM

4:30 PM

8:00 PM

6:30 PM

10:00 PM

8:30 PM

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

IST and GST on the World Map

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

IST Zone

→

GST 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

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

Time Conversion Guide: Sri Lanka to GST

Sri Lanka runs on India Standard Time (IST) at UTC+05:30. GST runs on Gulf Standard Time (GST) at UTC+04:00. That puts Sri Lanka 1 hour 30 minutes behind GST — a difference of -1h 30m at the current offsets.

In practice, when it is 9:00 AM in Sri Lanka it is 7:30 AM in GST. Midnight in Sri Lanka is 10:30 PM in GST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Sri Lanka to GST time conversion table

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

Why people convert Sri Lanka to GST time

Scheduling a call from Sri Lanka to GST: a 10:00 AM start in Sri Lanka lands at 8:30 AM in GST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Sri Lanka and GST are inside the 9-to-5 working day between 10:30 AM and 5:00 PM IST time (9:00 AM–3:30 PM GST). That is roughly 6 hours 30 minutes of usable overlap.
Booking travel or deliveries: tracking GST local time against Sri Lanka keeps pickup windows and arrival estimates honest across the -1h 30m offset.

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 10:30 AM–5:00 PM IST as the recurring meeting window if you work primarily from Sri Lanka and need GST 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 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 Sri Lanka and GST

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

Business hours overlap

Sri Lanka and GST share 6 hours of working-hours overlap (10:30 AM–5:00 PM IST), so scheduling a live meeting is straightforward.

Sri Lanka is 1 hour 30 minutes behind GST (IST UTC+05:30 → GST UTC+04:00). The shared working window is 10:30 AM–5:00 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 Sri Lanka and GST?

Sri Lanka (IST, UTC+05:30) is 1 hour 30 minutes behind GST (GST, UTC+04:00). The gap is currently -1h 30m.

How do I convert Sri Lanka time to GST time?

Add -1h 30m to Sri Lanka local time. For example, 9:00 AM in Sri Lanka is 7:30 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 -1h 30m offset from Sri Lanka.