Offset
The time difference between Mountain Time and Korea Standard Time is 15 hours.
Mountain Time (MDT) is behind Korea Standard Time (KST).
MDT: UTC-6
KST: UTC+9
Mountain Time is currently observing daylight saving time; Korea Standard Time is not.
When to schedule
Standard business hours (9 AM–5 PM, Mon–Fri) in Mountain Time and Korea Standard Time don't overlap on the same weekday. Korea Standard Time is 15 hours ahead of Mountain Time.
With some flexibility, there’s a workable window outside standard hours:
- 4 PM–8 PM in Mountain Time (7 AM–11 AM the next day in Korea Standard Time) — suggest 6:00 PM Mountain Time (9:00 AM Korea Standard Time).
This means an early start or late finish for one side, but it’s a reasonable slot for a one-off meeting.
This window may shift by an hour during daylight saving time.
Public holidays in 2026
National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.
United States
- New Year's DayThu, Jan 1
- Martin Luther King, Jr. DayMon, Jan 19
- Presidents DayMon, Feb 16
- Memorial DayMon, May 25
- Juneteenth National Independence DayFri, Jun 19
- Independence DayFri, Jul 3
- Labour DayMon, Sep 7
- Columbus DayMon, Oct 12
- Veterans DayWed, Nov 11
- Thanksgiving DayThu, Nov 26
- Christmas DayFri, Dec 25
South Korea
- New Year's DayThu, Jan 1
- Lunar New YearMon, Feb 16
- Lunar New YearTue, Feb 17
- Lunar New YearWed, Feb 18
- Independence Movement DayMon, Mar 2
- Labour DayFri, May 1
- Children's DayTue, May 5
- Buddha's BirthdayMon, May 25
- Local Election DayWed, Jun 3
- Memorial DaySat, Jun 6
- Constitution DayFri, Jul 17
- Liberation DayMon, Aug 17
- ChuseokThu, Sep 24
- ChuseokFri, Sep 25
- ChuseokSat, Sep 26
- National Foundation DayMon, Oct 5
- Hangul DayFri, Oct 9
- Christmas DayFri, Dec 25
About these zones
Mountain Time is also known as MST, or MDT. To call United States, dial +1.
Korea Standard Time is also known as KST. To call South Korea, dial +82.
Korea Standard Time is approximately 6,150 miles northwest of Mountain Time.
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| MST | KST | Day |
|---|---|---|
| 12:00 am | 3:00 pm | Same day |
| 1:00 am | 4:00 pm | Same day |
| 2:00 am | 5:00 pm | Same day |
| 3:00 am | 6:00 pm | Same day |
| 4:00 am | 7:00 pm | Same day |
| 5:00 am | 8:00 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 | +1 day |
| 10:00 am | 1:00 am | +1 day |
| 11:00 am | 2:00 am | +1 day |
| 12:00 pm | 3:00 am | +1 day |
| 1:00 pm | 4:00 am | +1 day |
| 2:00 pm | 5:00 am | +1 day |
| 3:00 pm | 6:00 am | +1 day |
| 4:00 pm | 7:00 am | +1 day |
| 5:00 pm | 8:00 am | +1 day |
| 6:00 pm | 9:00 am | +1 day |
| 7:00 pm | 10:00 am | +1 day |
| 8:00 pm | 11:00 am | +1 day |
| 9:00 pm | 12:00 pm | +1 day |
| 10:00 pm | 1:00 pm | +1 day |
| 11:00 pm | 2:00 pm | +1 day |
Daylight saving time
Mountain Time observes daylight saving time; Korea Standard Time does not. The offset between the two zones changes when Mountain Time transitions: on Sunday, November 1, 2026, clocks fall back from MDT to MST.
See the daylight saving time page for transition dates across every time zone.
Daylight today
- Sunrise
- 5:34 AM
- Sunset
- 8:25 PM
- Day length
- 14h 51m
- Sunrise
- 5:12 AM
- Sunset
- 7:51 PM
- Day length
- 14h 38m
Daylight overlap: 6h 12m — 2:12 PM–8:25 PM in Mountain Time (5:12 AM–11:25 AM in Korea Standard Time). Both locations are in daylight during this window.
Cities in these zones
Cities in Mountain Time
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Mountain Time
- BJC
- DEN
- OGD
- SLC
Airports in Korea Standard Time
- GMP
- ICN
- PUS
- TAE
- CJJ
- KWJ
- MWX
Related conversions
Common conversions
- What is 9:00 am MST in KST?
- 9:00 am MST is 12:00 am KST, the next day.
- What is 12:00 pm MST in KST?
- 12:00 pm MST is 3:00 am KST, the next day.
- What is 12:30 pm MST in KST?
- 12:30 pm MST is 3:30 am KST, the next day.
- What is 2:00 pm MST in KST?
- 2:00 pm MST is 5:00 am KST, the next day.
- What is 5:00 pm MST in KST?
- 5:00 pm MST is 8:00 am KST, the next day.
- What is 11:30 pm MST in KST?
- 11:30 pm MST is 2:30 pm KST, the next day.