Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

Denver to KST

+15h

Denver

MDTSOURCE

USA · UTC-06:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

KST

UTC+09:00

HH03

MM00

(next day)03:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Denver

KST

12:00 AM

3:00 PM

2:00 AM

5:00 PM

4:00 AM

7:00 PM

6:00 AM

9:00 PM

8:00 AM

11:00 PM

10:00 AM

1:00 AM+1

12:00 PM

3:00 AM+1

2:00 PM

5:00 AM+1

4:00 PM

7:00 AM+1

6:00 PM

9:00 AM+1

8:00 PM

11:00 AM+1

10:00 PM

1:00 PM+1

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

MDT and KST on the World Map

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

MDT Zone

→

KST Zone

Explore all world timezones interactively →

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

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

About Denver

Wikipedia

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.

Population:715,000

Metro:2.9 million

Business Hours:8:00 AM - 5:00 PM MST

Currency:USD ($)

Key Landmarks

Red Rocks AmphitheatreDenver Art MuseumUnion Station16th Street MallColorado State Capitol

Did You Know?

Denver International Airport is the largest airport in North America by land area.

Learn more about MDT timezone →

Understanding the +15h Gap: Denver vs KST

Denver runs on Mountain Daylight Time (MDT) at UTC-06:00, currently observing daylight saving time. KST runs on Korea Standard Time (KST) at UTC+09:00. That puts Denver 15 hours ahead of KST — a difference of +15h at the current offsets.

In practice, when it is 9:00 AM in Denver it is 12:00 AM in KST on the next day. Midnight in Denver is 3:00 PM in KST.Denver observes daylight saving time while KST does not, so the gap narrows or widens by an hour part of the year.

Denver to KST time conversion table

Denver (MDT)	KST (KST)	Day
12:00 AM	3:00 PM	same day
6:00 AM	9:00 PM	same day
7:00 AM	10:00 PM	same day
8:00 AM	11:00 PM	same day
9:00 AM	12:00 AM	next day
12:00 PM	3:00 AM	next day
3:00 PM	6:00 AM	next day
5:00 PM	8:00 AM	next day
6:00 PM	9:00 AM	next day
9:00 PM	12:00 PM	next day

Why people convert Denver to KST time

Scheduling a call from Denver to KST: a 10:00 AM start in Denver lands at 1:00 AM in KST the next day, so you can confirm the slot without doing the arithmetic yourself.
Handling a +15h gap: Denver and KST 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 KST is 12:00 AM in Denver.
Coordinating a Denver-based team with KST 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 MDT" 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 Denver takes the early slot, the next week KST does.
Denver: Clocks fall back on Sun, Nov 1, 2026. Re-check this page after that date because the offset changes and so does the +15h gap.

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).

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.

Best time to call between Denver and KST

With a +15h offset there is no overlap inside a normal 9 AM – 5 PM day. KST opens at 9:00 AM KST, which is 12:00 AM in Denver, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

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

Denver is 15 hours ahead of KST (MDT UTC-06:00 → KST UTC+09:00). 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

Denver

☀ Currently in DST

Standard: UTC-07:00 · DST: UTC-06:00

Clocks fall back on Sun, Nov 1, 2026

KST

Does not observe DST

Learn More About Time

Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between Denver and KST?

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

How do I convert Denver time to KST time?

Add +15h to Denver local time. For example, 9:00 AM in Denver is 12:00 AM in KST (next day).

What time is it in KST right now?

KST uses KST at UTC+09:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +15h offset from Denver.

What is the best time to call KST from Denver?

There is no shared working-hours window because of the +15h gap. The closest option is 1:00 PM in Denver, which is 4:00 AM in KST.

Which is ahead, Denver or KST?

Denver is 15 hours ahead of KST. When it is 12:00 PM in Denver it is 3:00 AM in KST.

Do Denver and KST use different time zones?

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

Does daylight saving time affect the Denver–KST 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 Denver's time zone?

MDT also covers Denver, Phoenix, Salt Lake City, Calgary, Edmonton, Albuquerque, El Paso, Tucson and 2 more.

Which countries use MDT, Denver's zone?

MDT is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).

Is there a day difference between Denver and KST?

Sometimes. The +15h gap is large enough that 8:00 PM or later in Denver already falls on the next day in KST.

What is the time difference between Denver and KST?

KST is +15h from Denver.

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 timezone is KST in?

KST operates on its local timezone.

What are the business hours in Denver?

Standard business hours in Denver are 8:00 AM - 5:00 PM MST.

Which countries use MST (Mountain Standard Time)?

MST is used in United States (Mountain), Canada (Alberta), Mexico (Chihuahua, Sonora).

Does MST observe daylight saving time?

Yes, MST switches to MDT during summer months.

What are some interesting 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.