GST to IST
+1h 30mGST
GSTSOURCEIST
ISTGreen rows indicate typical business hours (9 AM - 5 PM)
GST and IST on the World Map
The map below highlights the GST (Gulf Standard Time) and IST (India Standard Time) timezone regions across the globe.
GST – Gulf Standard Time
UTC+04:00Gulf Standard Time (GST) is used in the UAE, Oman, and other Gulf states, 4 hours ahead of UTC.
- •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.
IST – India Standard Time
UTC+05:30India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.
- •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.
Understanding the +1h 30m Gap: GST vs IST
GST runs on Gulf Standard Time (GST) at UTC+04:00. IST runs on India Standard Time (IST) at UTC+05:30. That puts GST 1 hour 30 minutes ahead of IST — a difference of +1h 30m at the current offsets.
In practice, when it is 9:00 AM in GST it is 10:30 AM in IST. Midnight in GST is 1:30 AM in IST. Neither zone observes daylight saving time, so the offset between them stays constant all year.
GST to IST time conversion table
| GST (GST) | IST (IST) | Day |
|---|---|---|
| 12:00 AM | 1:30 AM | same day |
| 6:00 AM | 7:30 AM | same day |
| 7:00 AM | 8:30 AM | same day |
| 8:00 AM | 9:30 AM | same day |
| 9:00 AM | 10:30 AM | same day |
| 12:00 PM | 1:30 PM | same day |
| 3:00 PM | 4:30 PM | same day |
| 5:00 PM | 6:30 PM | same day |
| 6:00 PM | 7:30 PM | same day |
| 9:00 PM | 10:30 PM | same day |
Why people convert GST to IST time
- Scheduling a call from GST to IST: a 10:00 AM start in GST lands at 11:30 AM in IST, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both GST and IST are inside the 9-to-5 working day between 9:00 AM and 3:30 PM GST time (10:30 AM–5:00 PM IST). That is roughly 6 hours 30 minutes of usable overlap.
- Watching a live event or market open: GST viewers need 10:30 AM in IST to catch a 9:00 AM start there, and 10:30 PM if the event is anchored to GST.
- Always state the zone abbreviation, not just the hour. "3:00 PM GST" is unambiguous; "3 PM" across a +1h 30m gap is not.
- Block 9:00 AM–3:30 PM GST as the recurring meeting window if you work primarily from GST and need IST 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 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.
Best time to call between GST and IST
Both GST and IST sit inside the 9 AM – 5 PM working day between 9:00 AM–3:30 PM GST, which is 10:30 AM–5:00 PM IST. That gives roughly 6 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
GST and IST share 6 hours of working-hours overlap (9:00 AM–3:30 PM GST), so scheduling a live meeting is straightforward.
GST is 1 hour 30 minutes ahead of IST (GST UTC+04:00 → IST UTC+05:30). The shared working window is 9:00 AM–3:30 PM GST. 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:
Frequently Asked Questions
What is the time difference between GST and IST?
GST (GST, UTC+04:00) is 1 hour 30 minutes ahead of IST (IST, UTC+05:30). The gap is currently +1h 30m.
How do I convert GST time to IST time?
Add +1h 30m to GST local time. For example, 9:00 AM in GST is 10:30 AM in IST.
What time is it in IST right now?
IST uses IST at UTC+05:30. Use the live converter at the top of this page — it updates in real time and already accounts for the +1h 30m offset from GST.
What is the best time to call IST from GST?
Call between 9:00 AM and 3:30 PM GST — that maps to 10:30 AM–5:00 PM IST and keeps both parties inside the working day.
Which is ahead, GST or IST?
GST is 1 hour 30 minutes ahead of IST. When it is 12:00 PM in GST it is 1:30 PM in IST.
Does daylight saving time affect the GST–IST difference?
Neither zone observes daylight saving time, so the +1h 30m offset between GST and IST is fixed all year.
Which other cities share GST's time zone?
GST also covers Dubai, Abu Dhabi, Muscat, Baku, Tbilisi.
Which countries use GST, GST's zone?
GST is used in UAE, Oman, Georgia, Azerbaijan, Mauritius.
Is there a day difference between GST and IST?
Not normally. The +1h 30m gap only pushes the date over for late-evening times.
What is the time difference between GST and IST?
IST is +1h 30m from GST.
What timezone is GST in?
GST operates on its local timezone.
What timezone is IST in?
IST operates on its local timezone.
Which countries use GST (Gulf Standard Time)?
GST is used in UAE, Oman, Georgia, Azerbaijan, Mauritius.
Does GST observe daylight saving time?
No, GST does not observe daylight saving time and remains at UTC+04:00 year-round.
What are some interesting 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.
Which cities are in the IST timezone?
Major cities in the IST timezone include Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad.
What is the UTC offset for IST?
India Standard Time (IST) is at UTC+05:30.
What should I know about the IST timezone?
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.
When is it midnight in GST, what time is it in IST?
When it is 12:00 AM (midnight) in GST (GST), it is +1h 30m later in IST (IST).
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