JST to MST
The difference month by month, the two long stretches it takes across the year, and what that means for a call between Tokyo and Denver.
How far apart are JST and MST?
MST is 15 hours behind JST for most of the year.
When it is 9:00 AM in Tokyo, it is still 6:00 PM the previous day in Denver.
Right now
The current reading appears once this page finishes loading.
How does the difference change month by month?
Any answer that quotes one number for this pair is wrong for part of the year. Here is the difference in force in each month of 2026, with the exact day it changes.
Show the month-by-month table
| Month | Difference | Changes on | New difference |
|---|---|---|---|
| January | −16:00 | No change | |
| February | −16:00 | No change | |
| March | −16:00 | −15:00 | |
| April | −15:00 | No change | |
| May | −15:00 | No change | |
| June | −15:00 | No change | |
| July | −15:00 | No change | |
| August | −15:00 | No change | |
| September | −15:00 | No change | |
| October | −15:00 | No change | |
| November | −15:00 | −16:00 | |
| December | −16:00 | No change |
When does the usual difference not hold?
It holds for one long stretch at a time. Only one of these two zones moves its clocks, so the difference takes two values across the year rather than breaking for a few weeks. These are the exact stretches.
Show every dated difference period
| From | Until | Difference | Days |
|---|---|---|---|
| −16:00 | 67 | ||
| −15:00 | 238 | ||
| −16:00 | 133 | ||
| −15:00 | 238 | ||
| −16:00 | 54 |