Korea Standard Time to Mountain Standard Time, with the offset for today's date rather than an average.
MST time
Mountain Standard Time is behind Korea Standard Time — noon in KST is 9:00 pm in MDT
KST todayUTC+09:00
MDT todayUTC-06:00
Working-hour overlap0 h
Common meeting hours converted from KST to MST
KST (Korea Standard Time)
MST (Mountain Standard Time)
Working hours in both?
7:00 am
4:00 pm previous day
No
8:00 am
5:00 pm previous day
No
9:00 am
6:00 pm previous day
No
10:00 am
7:00 pm previous day
No
11:00 am
8:00 pm previous day
No
12:00 pm
9:00 pm previous day
No
1:00 pm
10:00 pm previous day
No
2:00 pm
11:00 pm previous day
No
3:00 pm
12:00 am
No
4:00 pm
1:00 am
No
5:00 pm
2:00 am
No
6:00 pm
3:00 am
No
7:00 pm
4:00 am
No
8:00 pm
5:00 am
No
This calculator needs JavaScript to recalculate. The answer above was
worked out on 19 August 2026 and is correct for
that date; the site rebuilds every morning.
Rebuilt
· conventions last checked
Which zone this page means. South Korea does not observe daylight saving, so KST applies all year. It shares an offset with Japan. MST is standard time only; MDT (UTC-6) applies from March to November. Arizona stays on MST all year.
KST is ahead of MST by 15 hours today
On 19 August 2026, Korea Standard Time is on KST at
UTC+09:00 and Mountain Standard Time is on MDT at
UTC-06:00. The gap between them is
15 hours, with MST
behind. So 9:00 am in KST is
6:00 pm in MST, and 5:00 pm in KST is
2:00 am in MST. Going the other way, see MST to KST.
The gap is not constant, and that is the part that catches people out
Mountain Standard Time is currently observing daylight saving and changes next on 1 November 2026. Korea Standard Time does not observe daylight saving, so the gap moves only when Mountain Standard Time changes
its clocks — twice a year, by one hour.
When you can actually both be at work
Taking a working day as 9:00 am to 5:00 pm local at each end, there
are 0 overlapping hours
in a normal day. There is none: the two working days do not touch at all, so any live meeting between
Korea Standard Time and Mountain Standard Time has to sit outside somebody's normal hours. The table above shows
which end has the shorter stretch to give up.
Zone rules are set by legislation and change, sometimes at short notice. This page is
built against tzdata 2026a, last reviewed
2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads
your browser's own copy of the zone database, so if a rule has changed since this page was built the
live answer follows the new rule.
Every convention used above — whether the start date counts, how month ends are
clamped, which holidays close an office — is written out on the
methodology page, including the daylight-saving rules behind the 15-hour gap above.
The current offset is shown at the top of this page. It is computed for today's date rather than quoted as an average, because the two regions change their clocks on different dates and the gap is different for a few weeks each year.
Is KST the same as Korea Standard Time all year?
Not necessarily. Standard time and summer time are separate zones with separate abbreviations, so much of the year the technically correct abbreviation is the daylight one. The page states which is in force on today's date.
When do the clocks change in these zones?
The next change date for each zone is shown in the result panel, along with what the offset becomes afterwards.
What is a good meeting time between KST and MST?
The business-hours overlap window is shown below the converter. Where there is no overlap the page says so rather than suggesting an impossible time.