GST is 1 hour 30 minutes behind IST all year. So 12:00 PM IST = 10:30 AM GST.
IST to GST conversion table
| IST | GST |
|---|---|
| 12:00 AM | 10:30 PM −1 day |
| 1:00 AM | 11:30 PM −1 day |
| 2:00 AM | 12:30 AM |
| 3:00 AM | 1:30 AM |
| 4:00 AM | 2:30 AM |
| 5:00 AM | 3:30 AM |
| 6:00 AM | 4:30 AM |
| 7:00 AM | 5:30 AM |
| 8:00 AM | 6:30 AM |
| 9:00 AM | 7:30 AM |
| 10:00 AM | 8:30 AM |
| 11:00 AM | 9:30 AM |
| 12:00 PM | 10:30 AM |
| 1:00 PM | 11:30 AM |
| 2:00 PM | 12:30 PM |
| 3:00 PM | 1:30 PM |
| 4:00 PM | 2:30 PM |
| 5:00 PM | 3:30 PM |
| 6:00 PM | 4:30 PM |
| 7:00 PM | 5:30 PM |
| 8:00 PM | 6:30 PM |
| 9:00 PM | 7:30 PM |
| 10:00 PM | 8:30 PM |
| 11:00 PM | 9:30 PM |
IST and GST difference through 2027
The gap between the two zones on each date range, including daylight saving time changes:
| Dates | India Standard Time | Gulf Standard Time | Difference |
|---|---|---|---|
| Sep 30, 2026 – Dec 31, 2027 | IST (UTC+5:30) | GST (UTC+4) | GST 1 hour 30 minutes behind |
Best time to meet or call
- Working hours (9 AM–5 PM) overlap from 10:30 AM–5:00 PM IST (9:00 AM–3:30 PM GST), about 6 hours 30 minutes.
About India Standard Time (IST)
India uses one time zone, IST (UTC+5:30), all year. India does not observe daylight saving time, so its difference from the US and UK changes when they change their clocks. It's used in all of India, including New Delhi, Mumbai, Bengaluru, Hyderabad, Chennai and Kolkata.
About Gulf Standard Time (GST)
The UAE and Oman use GST (UTC+4) all year with no daylight saving time. It's used in Dubai, Abu Dhabi and Muscat.
Frequently asked questions
What time is 12 PM IST in GST?
12:00 PM IST is 10:30 AM GST.
How many hours ahead or behind is GST from IST?
GST is 1 hour 30 minutes behind IST, all year.
Does IST change for daylight saving time?
No. India uses one time zone, IST (UTC+5:30), all year. India does not observe daylight saving time, so its difference from the US and UK changes when they change their clocks.
Does GST change for daylight saving time?
No. The UAE and Oman use GST (UTC+4) all year with no daylight saving time.
What is the best time for a call between IST and GST?
Right now, working hours overlap from 10:30 AM–5:00 PM IST (9:00 AM–3:30 PM GST), about 6 hours 30 minutes.
More time zone conversions
Sources
Reviewed by Gurmej Singh, Founder, Divy Digital Hub · Last reviewed: Wednesday, September 30, 2026. All calculations run in your browser. Editorial policy.