GMT to KST Converter
Convert time between Greenwich Mean Time (GMT) and Korea Standard Time (KST)
Greenwich Mean Time (GMT)
Korea Standard Time (KST)
Time Difference
Korea Standard Time (KST) is 0 hours ahead of Greenwich Mean Time (GMT)
Select Date
Select Time
Quick Reference
| GMT | KST |
|---|---|
| 03:00 | 11:00 |
| 05:00 | 13:00 |
| 07:00 | 15:00 |
| 09:00 | 17:00 |
| 11:00 | 19:00 |
| 13:00 | 21:00 |
| 15:00 | 23:00 |
| 17:00 | 01:00 |
| 19:00 | 03:00 |
| 21:00 | 05:00 |
| 23:00 | 07:00 |
| 01:00 | 09:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
About GMT to KST Time Conversion
Converting time from Greenwich Mean Time (GMT) to Korea Standard Time (KST) is essential for coordinating activities between the United Kingdom and South Korea. GMT is UTC+0, while KST is UTC+9 with no daylight saving time observed in South Korea. This makes KST always 9 hours ahead of GMT — a stable, year-round offset. The gap narrows to 8 hours during British Summer Time (BST, UTC+1) when the UK shifts forward.
This time zone converter uses the IANA timezone database to ensure accurate results, factoring in BST transitions in the UK. South Korea's lack of daylight saving makes KST a predictable timezone for international scheduling. Whether you're coordinating UK-Seoul business meetings, planning travel between London and Korea, or keeping in touch with friends and family across these two regions, our converter delivers reliable results.
Common Use Cases for GMT to KST Conversion
Business & Work
- Scheduling early morning UK calls aligned with the Seoul afternoon
- Coordinating technology, K-pop, and entertainment industry operations between the UK and South Korea
- Planning project deadlines and conference calls with teams in Seoul or Busan
Personal & Travel
- Staying connected with family and friends between the UK and South Korea
- Planning travel between London and Seoul with accurate flight timing
- Following live K-pop releases, sports events, and Korean broadcasts from GMT regions
Time Zone Information
Greenwich Mean Time (GMT)
- UTC Offset: UTC+0 (UTC+1 during BST)
- IANA Timezone: Europe/London
- Daylight Saving: Last Sunday in March to Last Sunday in October
- Major Cities: London, Edinburgh, Cardiff, Belfast, Dublin
- Coverage: United Kingdom, Ireland, and other GMT-using regions
Korea Standard Time (KST)
- UTC Offset: UTC+9 (no DST observed)
- IANA Timezone: Asia/Seoul
- Daylight Saving: Korea Standard Time does not observe daylight saving time
- Major Cities: Seoul, Busan, Incheon, Daegu, Daejeon
- Coverage: South Korea (Republic of Korea)
Quick Reference: GMT to KST
Remember: KST is always 9 hours ahead of GMT. South Korea does not observe daylight saving time, so this offset is stable year-round (becomes 8 hours during UK BST).
Frequently Asked Questions
What is the time difference between GMT and KST?
Greenwich Mean Time (GMT) is UTC+0, while Korea Standard Time (KST) is UTC+9. KST is 9 hours ahead of GMT. When it's 12:00 PM (noon) in London, it's 9:00 PM in Seoul. South Korea does not observe daylight saving time, so this offset is stable year-round (it shifts to 8 hours during UK BST).
Does KST observe daylight saving time?
No. South Korea does not observe daylight saving time. KST is a fixed UTC+9 offset year-round. South Korea briefly used DST in the 1980s but discontinued it after the 1988 Seoul Olympics. Proposals to reintroduce DST have surfaced but none have passed, making KST one of the most stable major timezone identifiers.
How does British Summer Time affect this conversion?
When the UK observes British Summer Time (BST, UTC+1) from late March to late October, local UK clocks read 1 hour ahead of GMT. In pure GMT-to-KST terms, the offset stays 9 hours, but UK residents should remember the effective gap is 8 hours during BST since KST itself does not shift.
What are the best times for UK-Seoul business calls?
Seoul is 9 hours ahead of GMT, so workday windows barely overlap. The best window is early UK morning to late Seoul afternoon: 7:00–9:00 AM GMT equals 4:00–6:00 PM KST. During UK BST, that becomes 8:00–10:00 AM BST = 4:00–6:00 PM KST — a comfortable end-of-day window for Korean offices.
Does KST share its offset with other countries?
Yes. KST (UTC+9) is the same as Japan Standard Time (JST). Some Indonesian regions also use UTC+9. So the GMT-to-KST conversion applies equally to coordinating with Tokyo, Osaka, and other Japanese cities, as well as Indonesian provinces on Asia/Jayapura time.
Which regions use GMT?
Greenwich Mean Time (UTC+0) is the civil time of the United Kingdom, Ireland, Iceland, and parts of West Africa. The UK observes British Summer Time (BST, UTC+1) from late March to late October. Iceland and West African GMT countries do not observe DST and remain on UTC+0 year-round.
Pro Tips
- • KST is always 9 hours ahead of GMT — add 9 hours to any UK time to get Seoul time.
- • South Korea never observes DST — this conversion is stable year-round.
- • Best overlap: 7:00–9:00 AM GMT (4:00–6:00 PM KST) for end-of-day Seoul meetings.
- • Seoul shares the UTC+9 offset with Tokyo — same GMT-to-KST conversion applies to JST.
- • During UK BST (late March to late October), the effective gap drops to 8 hours.
- • Korean Stock Exchange opens at 9 AM KST (12 AM GMT) — useful for after-hours UK research.