Time zone converter

MST to JST

On Oct 23, 2026, Japan Standard Time is 15 hours ahead of Mountain Time: 9:00 AM MDT is 12:00 AM JST the next day. The gap changes during the year because of daylight saving time; the dates are below.

Mountain Time
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Current time in Mountain Time
Japan Standard Time
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Current time in Japan Standard Time
Pick a date and time to convert.

JST vs MST over the next 12 months

PeriodJST isExample
Oct 23, 2026 to Nov 1, 202615 hours ahead9:00 AM MDT = 12:00 AM JST (next day)
Nov 1, 2026 to Mar 14, 202716 hours ahead9:00 AM MST = 1:00 AM JST (next day)
Mar 14, 2027 onwards15 hours ahead9:00 AM MDT = 12:00 AM JST (next day)

MST to JST conversion table

Every hour of a weekday around Oct 23, 2026, in both zones.

Mountain TimeJapan Standard Time
12:00 AM3:00 PM
1:00 AM4:00 PM
2:00 AM5:00 PM
3:00 AM6:00 PM
4:00 AM7:00 PM
5:00 AM8:00 PM
6:00 AM9:00 PM
7:00 AM10:00 PM
8:00 AM11:00 PM
9:00 AM12:00 AM (next day)
10:00 AM1:00 AM (next day)
11:00 AM2:00 AM (next day)
12:00 PM3:00 AM (next day)
1:00 PM4:00 AM (next day)
2:00 PM5:00 AM (next day)
3:00 PM6:00 AM (next day)
4:00 PM7:00 AM (next day)
5:00 PM8:00 AM (next day)
6:00 PM9:00 AM (next day)
7:00 PM10:00 AM (next day)
8:00 PM11:00 AM (next day)
9:00 PM12:00 PM (next day)
10:00 PM1:00 PM (next day)
11:00 PM2:00 PM (next day)

Best time for a meeting

There is no 9-to-5 overlap; within an 8 AM–8 PM day the zones overlap for 3 hours on a weekday: 5:00 PM–8:00 PM MDT, which is 8:00 AM–11:00 AM JST.

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Daylight saving time

Mountain Time (MST/MDT)

  • Nov 1, 2026: clocks go back 1 hour at 2:00 AM (UTC−6 → UTC−7)
  • Mar 14, 2027: clocks go forward 1 hour at 2:00 AM (UTC−7 → UTC−6)

Where these clocks are used

  • Mountain Time (MST/MDT): Denver, Salt Lake City, Calgary. IANA zone America/Denver.
  • Japan Standard Time (JST): all of Japan. IANA zone Asia/Tokyo.

Questions

What time is it in JST when it is 9 AM MST?

On Oct 23, 2026, 9:00 AM MDT is 12:00 AM JST the next day. On other dates the answer can shift by an hour because of daylight saving time; the table of periods on this page gives each one.

How many hours ahead of MST is JST?

It depends on the date. Oct 23, 2026 to Nov 1, 2026: JST is 15 hours ahead. Nov 1, 2026 to Mar 14, 2027: JST is 16 hours ahead. Mar 14, 2027 onwards: JST is 15 hours ahead.

Do MST and JST observe daylight saving time?

Mountain Time switches to MDT (UTC−6) in summer and back to MST (UTC−7) in winter. Japan Standard Time stays on UTC+9 all year.

What is the best time for a meeting between MST and JST?

There is no 9-to-5 overlap; within an 8 AM–8 PM day the zones overlap for 3 hours on a weekday: 5:00 PM–8:00 PM MDT, which is 8:00 AM–11:00 AM JST.

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Related conversions

Computed from the IANA time zone database on Oct 23, 2026. Live clocks and the converter use your browser's copy of the same data.