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Seoul to MDT

-15h

Seoul

KSTSOURCE
South Korea · UTC+09:00
HH12
:
MM00
  
12:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM

MDT

MDT
UTC-06:00☀ DST active
HH09
:
MM00
  
(previous day)21:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
Seoul
MDT
12:00 AM
9:00 AM-1
2:00 AM
11:00 AM-1
4:00 AM
1:00 PM-1
6:00 AM
3:00 PM-1
8:00 AM
5:00 PM-1
10:00 AM
7:00 PM-1
12:00 PM
9:00 PM-1
2:00 PM
11:00 PM-1
4:00 PM
1:00 AM
6:00 PM
3:00 AM
8:00 PM
5:00 AM
10:00 PM
7:00 AM

Green rows indicate typical business hours (9 AM - 5 PM)

KST and MDT on the World Map

The map below highlights the KST (Korea Standard Time) and MDT (Mountain Daylight Time) timezone regions across the globe.

KSTMDTSeoulBusanIncheonDaeguDenverCalgaryEdmontonSalt Lake City
KST Zone
→
MDT Zone

Explore all world timezones interactively →

KST – Korea Standard Time

UTC+09:00

Korea Standard Time (KST) is the time zone for South Korea, 9 hours ahead of UTC.

Countries in KST
South KoreaNorth Korea
Major Cities in KST
SeoulBusanIncheonDaeguDaejeonPyongyang
Key Facts about KST
  • •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).
Daylight Saving:No – UTC+09:00 year-round
Learn more about KST on Wikipedia

MDT – Mountain Daylight Time

UTC-06:00

Mountain Daylight Time (MDT) is the daylight saving offset in the Mountain Time Zone, 6 hours behind UTC.

Countries in MDT
United States (Mountain)Canada (Alberta)
Major Cities in MDT
DenverCalgaryEdmontonSalt Lake CityBoise
Key Facts about MDT
  • •MDT shares the same offset as CST (UTC-06:00).
  • •Arizona does not switch to MDT, remaining on MST.
Daylight Saving:Yes – switches to MST
Learn more about MDT on Wikipedia

About Seoul

Wikipedia

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.

Population:9.7 million
Metro:25.5 million
Business Hours:9:00 AM - 6:00 PM KST
Currency:KRW (₩)
Stock Exchange:KRX (Korea Exchange)
Key Landmarks
Gyeongbokgung PalaceN Seoul TowerBukchon Hanok VillageDongdaemun Design PlazaCheonggyecheon Stream
Did You Know?

Seoul has the fastest average internet speed in the world.

Learn more about KST timezone →

Comparing Time Zones: Seoul and MDT

Seoul runs on Korean Standard Time (KST) at UTC+09:00. MDT runs on Mountain Daylight Time (MDT) at UTC-06:00. That puts Seoul 15 hours behind MDT — a difference of -15h at the current offsets.

In practice, when it is 9:00 AM in Seoul it is 6:00 PM in MDT on the previous day. Midnight in Seoul is 9:00 AM in MDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Seoul to MDT time conversion table

Seoul (KST)MDT (MDT)Day
12:00 AM9:00 AMprevious day
6:00 AM3:00 PMprevious day
7:00 AM4:00 PMprevious day
8:00 AM5:00 PMprevious day
9:00 AM6:00 PMprevious day
12:00 PM9:00 PMprevious day
3:00 PM12:00 AMsame day
5:00 PM2:00 AMsame day
6:00 PM3:00 AMsame day
9:00 PM6:00 AMsame day

Why people convert Seoul to MDT time

  • Scheduling a call from Seoul to MDT: a 10:00 AM start in Seoul lands at 7:00 PM in MDT the previous day, so you can confirm the slot without doing the arithmetic yourself.
  • Handling a -15h gap: Seoul and MDT 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 MDT is 6:00 PM in Seoul.
  • Coordinating a Seoul-based team with MDT contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
  • Always state the zone abbreviation, not just the hour. "3:00 PM KST" is unambiguous; "3 PM" across a -15h gap is not.
  • With a -15h gap there is no shared 9-to-5 window, so alternate the early start: one week Seoul takes the early slot, the next week MDT 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 MDT (Mountain Daylight Time)

Mountain Daylight Time (MDT) is observed during summer months in the Mountain Time Zone, except in Arizona which stays on MST year-round. MDT aligns with Central Standard Time (CST) at UTC-06:00.

Best time to call between Seoul and MDT

With a -15h offset there is no overlap inside a normal 9 AM – 5 PM day. MDT opens at 9:00 AM MDT, which is 6:00 PM in Seoul, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

Seoul and MDT have no shared working hours because of the -15h gap. Teams need to alternate early starts or rely on asynchronous handovers.

Seoul is 15 hours behind MDT (KST UTC+09:00 → MDT UTC-06:00). 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

MDT

☀ Currently in DST

Standard: UTC-07:00 · DST: UTC-06:00

Clocks fall back on Sun, Nov 1, 2026

Frequently Asked Questions

What is the time difference between Seoul and MDT?

Seoul (KST, UTC+09:00) is 15 hours behind MDT (MDT, UTC-06:00). The gap is currently -15h.

How do I convert Seoul time to MDT time?

Add -15h to Seoul local time. For example, 9:00 AM in Seoul is 6:00 PM in MDT (previous day).

What time is it in MDT right now?

MDT uses MDT at UTC-06:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -15h offset from Seoul.

What is the best time to call MDT from Seoul?

There is no shared working-hours window because of the -15h gap. The closest option is 1:00 PM in Seoul, which is 10:00 PM in MDT.

Which is behind, Seoul or MDT?

Seoul is 15 hours behind MDT. When it is 12:00 PM in Seoul it is 9:00 PM in MDT.

Do Seoul and MDT use different time zones?

Seoul (South Korea) uses KST at UTC+09:00, while MDT uses MDT at UTC-06:00. The IANA identifiers are Asia/Seoul and America/Denver.

Does daylight saving time affect the Seoul–MDT difference?

Neither zone observes daylight saving time, so the -15h offset between Seoul and MDT 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 MDT?

Sometimes. The -15h gap is large enough that 8:00 PM or later in Seoul already falls on the in MDT.

What is the time difference between Seoul and MDT?

MDT is -15h 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 MDT in?

MDT 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 MDT timezone?

Major cities in the MDT timezone include Denver, Calgary, Edmonton, Salt Lake City, Boise.

What is the UTC offset for MDT?

Mountain Daylight Time (MDT) is at UTC-06:00. During daylight saving time, it shifts to MST.

What should I know about the MDT timezone?

MDT shares the same offset as CST (UTC-06:00). Arizona does not switch to MDT, remaining on MST.

When is it midnight in Seoul, what time is it in MDT?

When it is 12:00 AM (midnight) in Seoul (KST), it is -15h later in MDT (MDT).