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).

Mumbai to GST

-1h 30m

Mumbai

ISTSOURCE

India · 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

Mumbai

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

About Mumbai

Wikipedia

Mumbai operates on India Standard Time (IST), UTC+5:30. As India's financial capital and home to BSE (Asia's oldest stock exchange), Mumbai timing is crucial for Asia markets.

Population:12.4 million

Metro:21.3 million

Business Hours:9:30 AM - 5:30 PM IST

Currency:INR (₹)

Stock Exchange:BSE (Bombay Stock Exchange), NSE

Key Landmarks

Gateway of IndiaChhatrapati Shivaji TerminusMarine DriveElephanta CavesHaji Ali Dargah

Did You Know?

The Mumbai local trains carry over 7.5 million passengers daily.

Learn more about IST timezone →

Comparing Time Zones: Mumbai and GST

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

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

Mumbai to GST time conversion table

Mumbai (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 Mumbai to GST time

Scheduling a call from Mumbai to GST: a 10:00 AM start in Mumbai lands at 8:30 AM in GST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Mumbai 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.
Watching a live event or market open: Mumbai viewers need 7:30 AM in GST to catch a 9:00 AM start there, and 1:30 AM if the event is anchored to Mumbai.

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 Mumbai 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 Mumbai and GST

Both Mumbai 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

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

Mumbai 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 Mumbai and GST?

Mumbai (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 Mumbai time to GST time?

Add -1h 30m to Mumbai local time. For example, 9:00 AM in Mumbai 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 Mumbai.

What is the best time to call GST from Mumbai?

Call between 10:30 AM and 5:00 PM IST — that maps to 9:00 AM–3:30 PM GST and keeps both parties inside the working day.

Which is behind, Mumbai or GST?

Mumbai is 1 hour 30 minutes behind GST. When it is 12:00 PM in Mumbai it is 10:30 AM in GST.

Do Mumbai and GST use different time zones?

Mumbai (India) uses IST at UTC+05:30, while GST uses GST at UTC+04:00. The IANA identifiers are Asia/Kolkata and Asia/Dubai.

Does daylight saving time affect the Mumbai–GST difference?

Neither zone observes daylight saving time, so the -1h 30m offset between Mumbai and GST is fixed all year.

Which other cities share Mumbai's time zone?

IST also covers Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad and 4 more.

Which countries use IST, Mumbai's zone?

IST is used in India, Sri Lanka.

Is there a day difference between Mumbai and GST?

Not normally. The -1h 30m gap only pushes the date over the previous day.

What is the time difference between Mumbai and GST?

GST is -1h 30m from Mumbai.

What timezone is Mumbai in?

Mumbai operates on India Standard Time (IST), UTC+5:30. As India's financial capital and home to BSE (Asia's oldest stock exchange), Mumbai timing is crucial for Asia markets.