KST to GMT Time Converter
GMT is 8 hours behind KST. KST is UTC+9:00, and The UK and Ireland are currently on BST (UTC+1:00).
Best Time to Call Between KST and GMT
Standard 9-to-5 hours in these two zones never overlap, so someone has to take the call outside their working day. The most workable window is 3:00 PM to 10:00 PM KST, which is 7:00 AM to 2:00 PM GMT.
both at work KST only GMT only neither — hours along the strip are KST.
Common Times Converted
KST on the left, GMT on the right.
KST to GMT: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| KST | GMT | Working hours |
|---|---|---|
| 12:00 AM | 4:00 PM prev day | GMT only |
| 1:00 AM | 5:00 PM prev day | — |
| 2:00 AM | 6:00 PM prev day | — |
| 3:00 AM | 7:00 PM prev day | — |
| 4:00 AM | 8:00 PM prev day | — |
| 5:00 AM | 9:00 PM prev day | — |
| 6:00 AM | 10:00 PM prev day | — |
| 7:00 AM | 11:00 PM prev day | — |
| 8:00 AM | 12:00 AM | — |
| 9:00 AM | 1:00 AM | KST only |
| 10:00 AM | 2:00 AM | KST only |
| 11:00 AM | 3:00 AM | KST only |
| 12:00 PM | 4:00 AM | KST only |
| 1:00 PM | 5:00 AM | KST only |
| 2:00 PM | 6:00 AM | KST only |
| 3:00 PM | 7:00 AM | KST only |
| 4:00 PM | 8:00 AM | KST only |
| 5:00 PM | 9:00 AM | GMT only |
| 6:00 PM | 10:00 AM | GMT only |
| 7:00 PM | 11:00 AM | GMT only |
| 8:00 PM | 12:00 PM | GMT only |
| 9:00 PM | 1:00 PM | GMT only |
| 10:00 PM | 2:00 PM | GMT only |
| 11:00 PM | 3:00 PM | GMT only |
What KST and GMT Actually Are
KST — Korea Standard Time
Seoul, Busan, Incheon. Standing at UTC+9:00 as written, and the region does not change its clocks, so that offset holds all year.
South Korea has used daylight saving only twice, most recently for the 1988 Seoul Olympics, and has kept a fixed offset since.
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 KST 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 KST
Cities on GMT
Frequently Asked Questions
What is the time difference between KST and GMT?
GMT is 8 hours behind KST. That is the live figure. Taken strictly as written, the gap between KST and GMT is 9 hours — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM KST in GMT?
9:00 AM KST is 1:00 AM GMT.
What are the best hours to schedule a call between KST and GMT?
Standard business hours in these two zones do not overlap at all, so one side has to work outside the 9-to-5. The most workable window is 3:00 PM to 10:00 PM KST, which is 7:00 AM to 2:00 PM GMT.
Does the difference between KST and GMT change during the year?
Yes. GMT observes daylight saving and KST 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 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.