GST to GMT Time Converter
GMT is 3 hours behind GST. GST is UTC+4:00, and The UK and Ireland are currently on BST (UTC+1:00).
Best Time to Call Between GST and GMT
Both zones are inside normal business hours between 12:00 PM and 5:00 PM GST — that's 9:00 AM to 2:00 PM GMT. That's a 5-hour window.
both at work GST only GMT only neither — hours along the strip are GST.
Common Times Converted
GST on the left, GMT on the right.
GST to GMT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| GST | GMT | Working hours |
|---|---|---|
| 12:00 AM | 9:00 PM prev day | — |
| 1:00 AM | 10:00 PM prev day | — |
| 2:00 AM | 11:00 PM prev day | — |
| 3:00 AM | 12:00 AM | — |
| 4:00 AM | 1:00 AM | — |
| 5:00 AM | 2:00 AM | — |
| 6:00 AM | 3:00 AM | — |
| 7:00 AM | 4:00 AM | — |
| 8:00 AM | 5:00 AM | — |
| 9:00 AM | 6:00 AM | GST only |
| 10:00 AM | 7:00 AM | GST only |
| 11:00 AM | 8:00 AM | GST only |
| 12:00 PM | 9:00 AM | Both zones |
| 1:00 PM | 10:00 AM | Both zones |
| 2:00 PM | 11:00 AM | Both zones |
| 3:00 PM | 12:00 PM | Both zones |
| 4:00 PM | 1:00 PM | Both zones |
| 5:00 PM | 2:00 PM | GMT only |
| 6:00 PM | 3:00 PM | GMT only |
| 7:00 PM | 4:00 PM | GMT only |
| 8:00 PM | 5:00 PM | — |
| 9:00 PM | 6:00 PM | — |
| 10:00 PM | 7:00 PM | — |
| 11:00 PM | 8:00 PM | — |
What GST and GMT Actually Are
GST — Gulf Standard Time
Dubai, Abu Dhabi, Sharjah, Muscat. Standing at UTC+4:00 as written, and the region does not change its clocks, so that offset holds all year. GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.
The Gulf states have never observed daylight saving, so Dubai's offset has been unchanged for decades — unusual stability for a region that grew as fast as it did.
GMT — Greenwich Mean Time
The UK and Ireland in winter, plus Iceland, Portugal and much of West Africa. Standing at UTC as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, October 25, 2026, to GMT. Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.
Britain ran an experiment from 1968 to 1971 on permanent UTC+1, abandoning GMT entirely. It was scrapped after complaints about dark winter mornings in Scotland.
What This Means in Practice
This gap is not fixed
GMT changes its clocks and GST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, October 25, 2026 unless someone resets it.
Major Cities in Each Zone
Cities on GST
Cities on GMT
Frequently Asked Questions
What is the time difference between GST and GMT?
GMT is 3 hours behind GST. That is the live figure. Taken strictly as written, the gap between GST and GMT is 4 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM GST in GMT?
9:00 AM GST is 6:00 AM GMT.
What are the best hours to schedule a call between GST and GMT?
Between 12:00 PM and 5:00 PM GST, which is 9:00 AM to 2:00 PM GMT. Both sides are inside normal business hours through that window.
Does the difference between GST and GMT change during the year?
Yes. GMT observes daylight saving and GST does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, October 25, 2026.
Does GST always mean Gulf Standard Time?
GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.
Does GMT always mean Greenwich Mean Time?
Often used loosely as a synonym for UTC. They differ by less than a second, so for scheduling they are interchangeable.