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South Korea to MST

-16h

South Korea

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

MST

MST
UTC-06:00☀ DST active
HH08
:
MM00
  
(previous day)20:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
South Korea
MST
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 MST on the World Map

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

KSTMSTSeoulBusanIncheonDaeguDenverPhoenixSalt Lake CityCalgary
KST Zone
→
MST 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

MST – Mountain Standard Time

UTC-07:00

Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.

Countries in MST
United States (Mountain)Canada (Alberta)Mexico (Chihuahua, Sonora)
Major Cities in MST
DenverPhoenixSalt Lake CityCalgaryEdmontonAlbuquerqueEl PasoTucsonBoiseCiudad Juárez
Key Facts about MST
  • •Arizona does not observe daylight saving time, staying on MST year-round.
  • •The Navajo Nation in Arizona does observe DST, unlike the rest of the state.
  • •Denver, the 'Mile High City', is the largest city fully in MST.
  • •MST covers 6 US states entirely and parts of several others.
Daylight Saving:Yes – switches to MDT
Learn more about MST on Wikipedia

Understanding the -16h Gap: South Korea vs MST

South Korea runs on Korean Standard Time (KST) at UTC+09:00. MST runs on Mountain Standard Time (MST) at UTC-07:00. That puts South Korea 16 hours behind MST — a difference of -16h at the current offsets.

In practice, when it is 9:00 AM in South Korea it is 5:00 PM in MST on the previous day. Midnight in South Korea is 8:00 AM in MST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

South Korea to MST time conversion table

South Korea (KST)MST (MST)Day
12:00 AM8:00 AMprevious day
6:00 AM2:00 PMprevious day
7:00 AM3:00 PMprevious day
8:00 AM4:00 PMprevious day
9:00 AM5:00 PMprevious day
12:00 PM8:00 PMprevious day
3:00 PM11:00 PMprevious day
5:00 PM1:00 AMsame day
6:00 PM2:00 AMsame day
9:00 PM5:00 AMsame day

Why people convert South Korea to MST time

  • Scheduling a call from South Korea to MST: a 10:00 AM start in South Korea lands at 6:00 PM in MST the previous day, so you can confirm the slot without doing the arithmetic yourself.
  • Handling a -16h gap: South Korea and MST 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 MST is 5:00 PM in South Korea.
  • Keeping family and friends in sync: knowing that 8:00 PM in South Korea is 4:00 AM in MST 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 -16h gap is not.
  • With a -16h gap there is no shared 9-to-5 window, so alternate the early start: one week South Korea takes the early slot, the next week MST 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 MST (Mountain Standard Time)

Mountain Standard Time (MST) covers the Rocky Mountain region of the United States and Canada. Arizona is notable for not observing daylight saving time, staying on MST year-round (except the Navajo Nation). The time zone includes major cities like Denver, Phoenix, Calgary, and Salt Lake City. During summer, most areas switch to Mountain Daylight Time (MDT, UTC-06:00).

Best time to call between South Korea and MST

With a -16h offset there is no overlap inside a normal 9 AM – 5 PM day. MST opens at 9:00 AM MST, which is 5:00 PM in South Korea, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

South Korea and MST have no shared working hours because of the -16h gap. Teams need to alternate early starts or rely on asynchronous handovers.

South Korea is 16 hours behind MST (KST UTC+09:00 → MST UTC-07:00). 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

South Korea

Does not observe DST

MST

☀ 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 South Korea and MST?

South Korea (KST, UTC+09:00) is 16 hours behind MST (MST, UTC-07:00). The gap is currently -16h.

How do I convert South Korea time to MST time?

Add -16h to South Korea local time. For example, 9:00 AM in South Korea is 5:00 PM in MST (previous day).

What time is it in MST right now?

MST uses MST at UTC-07:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -16h offset from South Korea.

What is the best time to call MST from South Korea?

There is no shared working-hours window because of the -16h gap. The closest option is 1:00 PM in South Korea, which is 9:00 PM in MST.

Which is behind, South Korea or MST?

South Korea is 16 hours behind MST. When it is 12:00 PM in South Korea it is 8:00 PM in MST.

Do South Korea and MST use different time zones?

South Korea (South Korea) uses KST at UTC+09:00, while MST uses MST at UTC-07:00. The IANA identifiers are Asia/Seoul and America/Denver.

Does daylight saving time affect the South Korea–MST difference?

Neither zone observes daylight saving time, so the -16h offset between South Korea and MST is fixed all year.

Which other cities share South Korea's time zone?

KST also covers Seoul, Busan, Incheon, Daegu, Daejeon, Pyongyang.

Which countries use KST, South Korea's zone?

KST is used in South Korea, North Korea.

Is there a day difference between South Korea and MST?

Sometimes. The -16h gap is large enough that 8:00 PM or later in South Korea already falls on the in MST.

What is the time difference between South Korea and MST?

MST is -16h from South Korea.

What timezone is South Korea in?

South Korea operates on its local timezone.

What timezone is MST in?

MST operates on its local timezone.

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 MST timezone?

Major cities in the MST timezone include Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson.

What is the UTC offset for MST?

Mountain Standard Time (MST) is at UTC-07:00. During daylight saving time, it shifts to MDT.

What should I know about the MST timezone?

Arizona does not observe daylight saving time, staying on MST year-round. The Navajo Nation in Arizona does observe DST, unlike the rest of the state.

When is it midnight in South Korea, what time is it in MST?

When it is 12:00 AM (midnight) in South Korea (KST), it is -16h later in MST (MST).