KST to Denver
-15hKST
KSTSOURCEDenver
MDTGreen 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 Standard 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).
MST – Mountain Standard Time
UTC-07:00Mountain Standard Time (MST) is the time zone for the Mountain region of North America, 7 hours behind UTC.
- •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.
About Denver
WikipediaDenver operates on Mountain Time (MST/MDT), 2 hours behind New York. As a tech and aerospace hub, Denver bridges West Coast and Central US business hours.
Denver International Airport is the largest airport in North America by land area.
KST vs Denver: Offsets, DST and Best Call Times
KST runs on Korea Standard Time (KST) at UTC+09:00. Denver runs on Mountain Daylight Time (MDT) at UTC-06:00, also currently on daylight saving time. That puts KST 15 hours behind Denver — a difference of -15h at the current offsets.
In practice, when it is 9:00 AM in KST it is 6:00 PM in Denver on the previous day. Midnight in KST is 9:00 AM in Denver.Denver observes daylight saving time while KST does not, so the gap narrows or widens by an hour part of the year.
KST to Denver time conversion table
| KST (KST) | Denver (MDT) | Day |
|---|---|---|
| 12:00 AM | 9:00 AM | previous day |
| 6:00 AM | 3:00 PM | previous day |
| 7:00 AM | 4:00 PM | previous day |
| 8:00 AM | 5:00 PM | previous day |
| 9:00 AM | 6:00 PM | previous day |
| 12:00 PM | 9:00 PM | previous day |
| 3:00 PM | 12:00 AM | same day |
| 5:00 PM | 2:00 AM | same day |
| 6:00 PM | 3:00 AM | same day |
| 9:00 PM | 6:00 AM | same day |
Why people convert KST to Denver time
- Scheduling a call from KST to Denver: a 10:00 AM start in KST lands at 7:00 PM in Denver the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -15h gap: KST and Denver 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 Denver is 6:00 PM in KST.
- Keeping family and friends in sync: knowing that 8:00 PM in KST is 5:00 AM in Denver 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 -15h gap is not.
- With a -15h gap there is no shared 9-to-5 window, so alternate the early start: one week KST takes the early slot, the next week Denver does.
- Denver: Clocks fall back on Sun, Nov 1, 2026. Any meeting series spanning that date will shift by an hour in local time.
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 KST and Denver
With a -15h offset there is no overlap inside a normal 9 AM – 5 PM day. Denver opens at 9:00 AM MDT, which is 6:00 PM in KST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
KST and Denver have no shared working hours because of the -15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
KST is 15 hours behind Denver (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
KST
Does not observe DST
Denver
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 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 KST and Denver?
KST (KST, UTC+09:00) is 15 hours behind Denver (MDT, UTC-06:00). The gap is currently -15h.
How do I convert KST time to Denver time?
Add -15h to KST local time. For example, 9:00 AM in KST is 6:00 PM in Denver (previous day).
What time is it in Denver right now?
Denver 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 KST.
What is the best time to call Denver from KST?
There is no shared working-hours window because of the -15h gap. The closest option is 1:00 PM in KST, which is 10:00 PM in Denver.
Which is behind, KST or Denver?
KST is 15 hours behind Denver. When it is 12:00 PM in KST it is 9:00 PM in Denver.
Do KST and Denver use different time zones?
KST uses KST at UTC+09:00, while Denver (USA) uses MDT at UTC-06:00. The IANA identifiers are Asia/Seoul and America/Denver.
Does daylight saving time affect the KST–Denver difference?
Yes at the moment: Denver is on daylight saving time and KST is not, so the -15h gap shifts by an hour when exactly one of them changes clocks.
Which other cities share KST's time zone?
KST also covers Seoul, Busan, Incheon, Daegu, Daejeon, Pyongyang.
Which countries use KST, KST's zone?
KST is used in South Korea, North Korea.
Is there a day difference between KST and Denver?
Sometimes. The -15h gap is large enough that 8:00 PM or later in KST already falls on the in Denver.
What is the time difference between KST and Denver?
Denver is -15h from KST.
What timezone is KST in?
KST operates on its local timezone.
What timezone is Denver in?
Denver operates on Mountain Time (MST/MDT), 2 hours behind New York. As a tech and aerospace hub, Denver bridges West Coast and Central US business hours.
What are the business hours in Denver?
Standard business hours in Denver are 8:00 AM - 5:00 PM MST.
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 KST, what time is it in Denver?
When it is 12:00 AM (midnight) in KST (KST), it is -15h later in Denver (MST).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More KST time conversions
- kst to seoul
- kst to south korea
- kst to new york
- kst to london
- kst to dubai
- kst to tokyo
- kst to singapore
- kst to sydney
- kst to los angeles
- kst to paris
- kst to delhi
- kst to mumbai
- kst to berlin
- kst to hong kong
- kst to toronto
- kst to kathmandu
- new york to kst
- london to kst
- dubai to kst
- tokyo to kst
- singapore to kst
- sydney to kst
- los angeles to kst
- paris to kst
- delhi to kst
- mumbai to kst
- berlin to kst
- hong kong to kst
- toronto to kst
- kathmandu to kst
See every conversion from KST →·See every conversion from Denver →