Time Difference Between Tokyo and Mountain Time
As of 12 October 2026, Mountain Time is 15 hours behind Tokyo. 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
21:45
Mon, Oct 12, 2026
UTC+9 · Asia/Tokyo
Mountain Time, United States
-15h
06:45
Mon, Oct 12, 2026
UTC-6 · MDT · America/Denver
Mountain Time is 15 hours behind Tokyo.
Time zone details
| Place | Local date | Time zone | UTC offset | Summer time |
|---|---|---|---|---|
| Tokyo | Monday, October 12, 2026 | Asia/Tokyo | UTC+9 | Not observed |
| Mountain Time | Monday, October 12, 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: Tokyo to Mountain Time
Every hour of today in Tokyo and what it is in Mountain Time. Highlighted rows fall inside Mountain Time working hours (09:00–18:00).
| Tokyo | 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 |
| Tokyo | 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 Tokyo 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 Tokyo (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 Tokyo — 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.
Tokyo and Mountain Time: common questions
What is the time difference between Tokyo and Mountain Time?
As of 12 October 2026, Mountain Time is 15 hours behind Tokyo. The gap is not fixed: across the year, Mountain Time ranges from 16 hours behind to 15 hours behind relative to Tokyo, as clocks change. The calculator on this page always shows the difference for right now.
When it is 9:00 AM in Tokyo, 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 Tokyo?
Mountain Time is behind Tokyo by 15 hours at the moment. In practical terms, the working day in Mountain Time starts and ends later in Tokyo terms.
Do Tokyo and Mountain Time observe daylight saving time?
Mountain Time changes its clocks twice a year; Tokyo 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 Tokyo.
What is the best time to call Mountain Time from Tokyo?
Standard working hours in Tokyo and Mountain Time do not overlap at all, so one side has to take the call outside office hours. Early morning in Tokyo 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, October 12, 2026 UTC and refresh in your browser.