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).

KST to MDT

-15h

KST

KSTSOURCE

UTC+09:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

MDT

UTC-06:00☀ DST active

HH09

MM00

(previous day)21:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

KST

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.

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

Comparing Time Zones: KST and MDT

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

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

KST to MDT time conversion table

KST (KST)	MDT (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 MDT time

Scheduling a call from KST to MDT: a 10:00 AM start in KST 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: KST 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 KST.
Watching a live event or market open: KST viewers need 6:00 PM in MDT to catch a 9:00 AM start there, and 3:00 PM if the event is anchored to KST.

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 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 KST 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 KST, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

KST and MDT 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 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

KST

Does not observe DST

MDT

☀ 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:

⏳

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 KST and MDT?

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

How do I convert KST time to MDT time?

Add -15h to KST local time. For example, 9:00 AM in KST 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 KST.