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IST to GST

-1h 30m

IST

ISTSOURCE
UTC+05:30
HH12
:
MM00
  
12:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM

GST

GST
UTC+04:00
HH10
:
MM30
  
10:30 (24-hr)
12 AM6 AM12 PM6 PM12 AM
IST
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.

ISTGSTMumbaiDelhiBangaloreKolkataDubaiAbu DhabiMuscatBaku
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

IST vs GST: Offsets, DST and Best Call Times

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

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

IST to GST time conversion table

IST (IST)GST (GST)Day
12:00 AM10:30 PMprevious day
6:00 AM4:30 AMsame day
7:00 AM5:30 AMsame day
8:00 AM6:30 AMsame day
9:00 AM7:30 AMsame day
12:00 PM10:30 AMsame day
3:00 PM1:30 PMsame day
5:00 PM3:30 PMsame day
6:00 PM4:30 PMsame day
9:00 PM7:30 PMsame day

Why people convert IST to GST time

  • Scheduling a call from IST to GST: a 10:00 AM start in IST lands at 8:30 AM in GST, so you can confirm the slot without doing the arithmetic yourself.
  • Finding shared working hours: both IST 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.
  • Keeping family and friends in sync: knowing that 8:00 PM in IST is 6:30 PM in GST makes it easy to avoid calling at 3 AM.
  • 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 IST 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 IST and GST

Both IST 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

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

IST 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.

Frequently Asked Questions

What is the time difference between IST and GST?

IST (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 IST time to GST time?

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

What is the best time to call GST from IST?

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, IST or GST?

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

Does daylight saving time affect the IST–GST difference?

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

Which other cities share IST's time zone?

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

Which countries use IST, IST's zone?

IST is used in India, Sri Lanka.

Is there a day difference between IST and GST?

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

What is the time difference between IST and GST?

GST is -1h 30m from IST.

What timezone is IST in?

IST operates on its local timezone.

What timezone is GST in?

GST operates on its local timezone.

Which countries use IST (India Standard Time)?

IST is used in India, Sri Lanka.

Does IST observe daylight saving time?

No, IST does not observe daylight saving time and remains at UTC+05:30 year-round.

What are some interesting 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.

Which cities are in the GST timezone?

Major cities in the GST timezone include Dubai, Abu Dhabi, Muscat, Baku, Tbilisi.

What is the UTC offset for GST?

Gulf Standard Time (GST) is at UTC+04:00.

What should I know about the GST timezone?

Dubai uses GST year-round with no daylight saving time. GST is 9 hours ahead of EST and 4 hours ahead of GMT.

When is it midnight in IST, what time is it in GST?

When it is 12:00 AM (midnight) in IST (IST), it is -1h 30m later in GST (GST).