JST to MST Time Converter
Convert Japan Standard Time to Mountain Time instantly.
Scroll the timeline to check any hour of the day.
Japan Standard Time
JST
5:25
Mountain Time
MST
2:25
JST is on standard time (JST), while MST is on daylight savings (MDT) right now.
Search any city, build a custom world clock, and plan across more time zones and options in the FlutterTime app. Free.
How the JST to MST time difference works
MST is 15 hours behind JST. Japan Standard Time (JST) is the time zone of Japan. Mountain Time (MST) is the US Mountain time zone. For example, 9:00 AM JST is 6:00 PM MST. Scroll the timeline above to convert any moment, or use the chart below for a quick reference.
Time difference
15 hours
Daylight saving
MST only
JST offset
UTC+9
MST offset
UTC-7
JST to MST conversion chart
| Japan Standard Time (JST) | Mountain Time (MST) |
|---|---|
| 12:00 AM | 9:00 AM -1 day |
| 1:00 AM | 10:00 AM -1 day |
| 2:00 AM | 11:00 AM -1 day |
| 3:00 AM | 12:00 PM -1 day |
| 4:00 AM | 1:00 PM -1 day |
| 5:00 AM | 2:00 PM -1 day |
| 6:00 AM | 3:00 PM -1 day |
| 7:00 AM | 4:00 PM -1 day |
| 8:00 AM | 5:00 PM -1 day |
| 9:00 AM | 6:00 PM -1 day |
| 10:00 AM | 7:00 PM -1 day |
| 11:00 AM | 8:00 PM -1 day |
| 12:00 PM | 9:00 PM -1 day |
| 1:00 PM | 10:00 PM -1 day |
| 2:00 PM | 11:00 PM -1 day |
| 3:00 PM | 12:00 AM |
| 4:00 PM | 1:00 AM |
| 5:00 PM | 2:00 AM |
| 6:00 PM | 3:00 AM |
| 7:00 PM | 4:00 AM |
| 8:00 PM | 5:00 AM |
| 9:00 PM | 6:00 AM |
| 10:00 PM | 7:00 AM |
| 11:00 PM | 8:00 AM |
Cities in each time zone
Japan Standard Time (JST)
TokyoOsakaYokohamaNagoyaSapporo
Mountain Time (MST)
DenverSalt Lake CityAlbuquerqueBoiseColorado Springs
JST to MST questions
Is MST ahead of or behind JST?
MST is 15 hours behind JST. So 9:00 AM JST is 6:00 PM MST, and 5:00 PM JST is 2:00 AM MST.
What time is it in MST when it is 12:00 PM JST?
When it is 12:00 PM (noon) JST in Japan Standard Time, it is 9:00 PM MST in Mountain Time.
How many hours difference is there between JST and MST?
There is a 15 hours difference. Mountain Time (MST) runs 15 hours behind Japan Standard Time (JST).
Do JST and MST observe daylight saving time?
Mountain Time observes daylight saving time but Japan Standard Time does not, so the difference between them changes by an hour twice a year.
What is the best time to schedule a meeting between JST and MST?
A standard 9-to-5 workday in Japan Standard Time and Mountain Time does not overlap, so pick the early morning in the later zone or the late evening in the earlier zone.
Which cities use JST and MST?
Japan Standard Time (JST) covers cities such as Tokyo, Osaka, Yokohama, Nagoya, Sapporo. Mountain Time (MST) covers cities such as Denver, Salt Lake City, Albuquerque, Boise, Colorado Springs.