Seoul to GMT
-9hSeoul
KSTSOURCEGMT
GMTGreen rows indicate typical business hours (9 AM - 5 PM)
KST and GMT on the World Map
The map below highlights the KST (Korea Standard Time) and GMT (Greenwich Mean Time) timezone regions across the globe.
KST – Korea Standard Time
UTC+09:00Korea Standard Time (KST) is the time zone for South Korea, 9 hours ahead of UTC.
- •South Korea does not observe daylight saving time.
- •Seoul is home to Samsung, LG, and Hyundai headquarters.
- •KST is the same offset as JST (UTC+09:00).
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
About Seoul
WikipediaSeoul operates on Korea Standard Time (KST), UTC+9, same as Japan. As a global tech and entertainment hub, Seoul coordinates with East Asian markets.
Seoul has the fastest average internet speed in the world.
Seoul vs GMT: Offsets, DST and Best Call Times
Seoul runs on Korean Standard Time (KST) at UTC+09:00. GMT runs on Greenwich Mean Time (GMT) at UTC+00:00. That puts Seoul 9 hours behind GMT — a difference of -9h at the current offsets.
In practice, when it is 9:00 AM in Seoul it is 12:00 AM in GMT. Midnight in Seoul is 3:00 PM in GMT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Seoul to GMT time conversion table
| Seoul (KST) | GMT (GMT) | Day |
|---|---|---|
| 12:00 AM | 3:00 PM | previous day |
| 6:00 AM | 9:00 PM | previous day |
| 7:00 AM | 10:00 PM | previous day |
| 8:00 AM | 11:00 PM | previous day |
| 9:00 AM | 12:00 AM | same day |
| 12:00 PM | 3:00 AM | same day |
| 3:00 PM | 6:00 AM | same day |
| 5:00 PM | 8:00 AM | same day |
| 6:00 PM | 9:00 AM | same day |
| 9:00 PM | 12:00 PM | same day |
Why people convert Seoul to GMT time
- Scheduling a call from Seoul to GMT: a 10:00 AM start in Seoul lands at 1:00 AM in GMT, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -9h gap: Seoul and GMT have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in GMT is 12:00 AM in Seoul.
- Keeping family and friends in sync: knowing that 8:00 PM in Seoul is 11:00 AM in GMT makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM KST" is unambiguous; "3 PM" across a -9h gap is not.
- With a -9h gap there is no shared 9-to-5 window, so alternate the early start: one week Seoul takes the early slot, the next week GMT does.
About KST (Korea Standard Time)
Korea Standard Time (KST) is the time zone used in South Korea. It shares the same UTC offset as Japan Standard Time but is a distinct time zone. South Korea does not observe daylight saving time. Seoul, the capital, is a major global tech and business hub.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
Best time to call between Seoul and GMT
With a -9h offset there is no overlap inside a normal 9 AM – 5 PM day. GMT opens at 9:00 AM GMT, which is 12:00 AM in Seoul, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Seoul and GMT have no shared working hours because of the -9h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Seoul is 9 hours behind GMT (KST UTC+09:00 → GMT UTC+00:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Seoul
Does not observe DST
GMT
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
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 Seoul and GMT?
Seoul (KST, UTC+09:00) is 9 hours behind GMT (GMT, UTC+00:00). The gap is currently -9h.
How do I convert Seoul time to GMT time?
Add -9h to Seoul local time. For example, 9:00 AM in Seoul is 12:00 AM in GMT.
What time is it in GMT right now?
GMT uses GMT at UTC+00:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -9h offset from Seoul.
What is the best time to call GMT from Seoul?
There is no shared working-hours window because of the -9h gap. The closest option is 1:00 PM in Seoul, which is 4:00 AM in GMT.
Which is behind, Seoul or GMT?
Seoul is 9 hours behind GMT. When it is 12:00 PM in Seoul it is 3:00 AM in GMT.
Do Seoul and GMT use different time zones?
Seoul (South Korea) uses KST at UTC+09:00, while GMT uses GMT at UTC+00:00. The IANA identifiers are Asia/Seoul and Europe/London.
Does daylight saving time affect the Seoul–GMT difference?
Neither zone observes daylight saving time, so the -9h offset between Seoul and GMT is fixed all year.
Which other cities share Seoul's time zone?
KST also covers Seoul, Busan, Incheon, Daegu, Daejeon, Pyongyang.
Which countries use KST, Seoul's zone?
KST is used in South Korea, North Korea.
Is there a day difference between Seoul and GMT?
Not normally. The -9h gap only pushes the date over the previous day.
What is the time difference between Seoul and GMT?
GMT is -9h from Seoul.
What timezone is Seoul in?
Seoul operates on Korea Standard Time (KST), UTC+9, same as Japan. As a global tech and entertainment hub, Seoul coordinates with East Asian markets.
What timezone is GMT in?
GMT operates on its local timezone.
What are the business hours in Seoul?
Standard business hours in Seoul are 9:00 AM - 6:00 PM KST.
Which countries use KST (Korea Standard Time)?
KST is used in South Korea, North Korea.
Does KST observe daylight saving time?
No, KST does not observe daylight saving time and remains at UTC+09:00 year-round.
What are some interesting facts about KST?
South Korea does not observe daylight saving time. Seoul is home to Samsung, LG, and Hyundai headquarters.
Which cities are in the GMT timezone?
Major cities in the GMT timezone include London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar.
What is the UTC offset for GMT?
Greenwich Mean Time (GMT) is at UTC+00:00. During daylight saving time, it shifts to BST.
What should I know about the GMT timezone?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
When is it midnight in Seoul, what time is it in GMT?
When it is 12:00 AM (midnight) in Seoul (KST), it is -9h later in GMT (GMT).
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