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JST to MST Converter

JST to MST, made simple. MST is 16 hours behind JST. Change the time or date in either card and the conversion follows along instantly.

MDT is 15 hours behind JST−1 day
From
JST

Now in Tokyo: 2:54:04 AM JST

To
−1 day
MDT

Now in Denver: 11:54:04 AM MDT

On this date Denver observes MDT. MST is in effect during standard-time (non-summer) months.

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Daylight saving notes

In the United States and Canada, daylight saving time runs from the second Sunday in March to the first Sunday in November. That affects Mountain Standard Time (MST).

JST to MST conversion chart

For example, a 9:00 AM JST meeting takes place at 5:00 PM MST (−1 day). Concretely, when Tokyo (JST) and Denver (MST) set up a call, mST is 16 hours behind JST.

Japan Standard Time to Mountain Standard Time conversion chart
JST timeMST time
12:00 AM8:00 AM−1 day
1:00 AM9:00 AM−1 day
2:00 AM10:00 AM−1 day
3:00 AM11:00 AM−1 day
4:00 AM12:00 PM−1 day
5:00 AM1:00 PM−1 day
6:00 AM2:00 PM−1 day
7:00 AM3:00 PM−1 day
8:00 AM4:00 PM−1 day
9:00 AM5:00 PM−1 day
10:00 AM6:00 PM−1 day
11:00 AM7:00 PM−1 day
12:00 PM8:00 PM−1 day
1:00 PM9:00 PM−1 day
2:00 PM10:00 PM−1 day
3:00 PM11:00 PM−1 day
4:00 PM12:00 AM
5:00 PM1:00 AM
6:00 PM2:00 AM
7:00 PM3:00 AM
8:00 PM4:00 AM
9:00 PM5:00 AM
10:00 PM6:00 AM
11:00 PM7:00 AM

This chart uses the fixed JST and MST offsets; the live converter above follows current daylight saving.

Convert JST to MST Time Zone

Below are the answers people search for most when converting Japan Standard Time (JST) to Mountain Standard Time (MST).

How does the JST to MST converter work?

It takes three quick steps:

  1. Click the JST field on the left and pick the time you want to convert.
  2. The matching MST time updates on the right automatically — there’s no button to press.
  3. Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.

JST vs MST: what's the time gap?

MST is 16 hours behind JST. In everyday terms, once you know the time on one side you just subtract 16 hours to get the other — so a call between Tokyo and Denver is always 16 hours apart.

What time is it in MST right now?

Right now the time in Mountain Standard Time (MST) is Monday, June 29, 2026 · 10:54:04 AM. It ticks every second, so you’re always looking at the live MST clock.

What time is it in JST right now?

And in Japan Standard Time (JST), it’s currently Tuesday, June 30, 2026 · 2:54:04 AM. Compare the two and the 16 hours gap is easy to see.

When is a good time to schedule a JST to MST meeting?

For example, a 9:00 AM JST meeting takes place at 5:00 PM MST (−1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.

How does daylight saving affect JST to MST?

The labels JST and MST are fixed offsets, so the result on this page is always exact. One side switches between standard and summer time while the other stays put, so the real-world gap can shift by an hour for part of the year. It's worth checking which label a region is actually using before you lock in a time.

Why can you trust this JST to MST converter?

Every conversion here is calculated from the IANA time zone database — the same source your phone, computer, and browser rely on. Plenty of tools hard-code a single offset, which quietly goes wrong whenever a region changes its rules or flips for daylight saving. We follow the real rules instead, so JST to MST stays accurate for today and for any past or future date you type in.

Convert JST to other time zones

Convert to MST from other time zones

Frequently asked questions

How many hours behind JST is MST?

MST is 16 hours behind JST — a fixed 16 hours difference, since both are fixed-offset labels.

What time is it in MST when it's 12:00 PM JST?

When it's 12:00 PM (noon) JST, it's 8:00 PM MST the previous day.

Do JST or MST use daylight saving time?

Japan Standard Time (JST) is a fixed offset with no daylight saving; Mountain Standard Time (MST) observes daylight saving, alternating with MDT.

Why might the real-world JST–MST difference change during the year?

The labels JST and MST are fixed offsets, so this converter is always exact. But Mountain Standard Time's region switches between standard and summer time, so for part of the year you may actually want JST to MDT. Always check which label a region is currently using before you schedule.