Time Difference Between Japan and Mountain Time
As of 31 August 2026, Mountain Time is 15 hours behind Japan. That number is not constant. Over the course of a year, because of daylight saving changes, Mountain Time, United States ranges from 16 hours behind to 15 hours behind relative to Tokyo, Japan. The calculator below is always up to date.
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Tokyo, Japan
07:34
Tue, Sep 1, 2026
UTC+9 · Asia/Tokyo
Mountain Time, United States
-15h16:34
Mon, Aug 31, 2026
UTC-6 · MDT · America/Denver
Mountain Time is 15 hours behind Japan.
When it is 07:34 in Japan, it is already the previous day in Mountain Time.
Time zone details
| Place | Local date | Time zone | UTC offset | Summer time |
|---|---|---|---|---|
| Japan | Tuesday, September 1, 2026 | Asia/Tokyo | UTC+9 | Not observed |
| Mountain Time | Monday, August 31, 2026 | MDTAmerica/Denver | UTC-6 | Active now |
Mountain Time: Covers Denver and most of the Rocky Mountain states. Switches between MST (UTC-7) and MDT (UTC-6) with daylight saving — unlike Arizona, which stays on MST year-round.
Hour by hour: Japan to Mountain Time
Every hour of today in Japan and what it is in Mountain Time. Highlighted rows fall inside Mountain Time working hours (09:00–18:00).
| Japan | Mountain Time |
|---|---|
| 00:00 | 09:00prev day |
| 01:00 | 10:00prev day |
| 02:00 | 11:00prev day |
| 03:00 | 12:00prev day |
| 04:00 | 13:00prev day |
| 05:00 | 14:00prev day |
| 06:00 | 15:00prev day |
| 07:00 | 16:00prev day |
| 08:00 | 17:00prev day |
| 09:00 | 18:00prev day |
| 10:00 | 19:00prev day |
| 11:00 | 20:00prev day |
| Japan | Mountain Time |
|---|---|
| 12:00 | 21:00prev day |
| 13:00 | 22:00prev day |
| 14:00 | 23:00prev day |
| 15:00 | 00:00 |
| 16:00 | 01:00 |
| 17:00 | 02:00 |
| 18:00 | 03:00 |
| 19:00 | 04:00 |
| 20:00 | 05:00 |
| 21:00 | 06:00 |
| 22:00 | 07:00 |
| 23:00 | 08:00 |
Best time to call or meet
Overlapping working hours
No overlap
Standard working hours in Japan and Mountain Time never overlap. Someone has to start early or finish late — the calling window below is the practical compromise.
Reasonable calling hours
08:00–12:00 in Japan (17:00–21:00 in Mountain Time)
Both people are awake and available between 08:00 and 21:00 local time during this window.
When this difference changes
Mountain Time puts its clocks back on Sunday, November 1, 2026
The local offset moves from UTC-6 to UTC-7. After that date, Mountain Time is 16 hours behind Japan — instead of 15 hours behind, as it is today.
Planning something with more than two places?
Adding a third city usually kills the obvious answer. The Meeting Time Finder takes up to five cities at once and shows only the hours that work for everybody.
Japan and Mountain Time: common questions
What is the time difference between Japan and Mountain Time?
As of 31 August 2026, Mountain Time is 15 hours behind Japan. The gap is not fixed: across the year, Mountain Time ranges from 16 hours behind to 15 hours behind relative to Japan, as clocks change. The calculator on this page always shows the difference for right now.
When it is 9:00 AM in Japan, what time is it in Mountain Time?
It is 06:00 PM in Mountain Time, United States. Use the time field in the calculator above to check any other hour.
Is Mountain Time ahead of or behind Japan?
Mountain Time is behind Japan by 15 hours at the moment. In practical terms, the working day in Mountain Time starts and ends later in Japan terms.
Do Japan and Mountain Time observe daylight saving time?
Mountain Time changes its clocks twice a year; Japan does not. The difference therefore shifts by an hour when Mountain Time switches: across the year, Mountain Time ranges from 16 hours behind to 15 hours behind relative to Japan.
What is the best time to call Mountain Time from Japan?
Standard working hours in Japan and Mountain Time do not overlap at all, so one side has to take the call outside office hours. Early morning in Japan or late evening is usually the least disruptive option.
Related comparisons
Local dates shown for Tokyo, Japan (UTC+9) and Mountain Time, United States (UTC-6) were generated on Monday, August 31, 2026 UTC and refresh in your browser.