Clockjumper

Timezone conversion

JST to MST Time — Convert Japan Standard Time to Mountain Standard Time (US)

MST is currently 15 hours behind JST. The gap shifts across the year: around January MST is 16 hours behind JST, and around July it is 15 hours behind JST, because one or both zones observe daylight saving.

MST is currently 15 hours behind JST.

JST • JST (UTC+9)
11:32 PM
Thursday, Sep 10
MST • MDT (UTC-6)
8:32 AM
Thursday, Sep 10

Abbreviation disambiguation

MST is Mountain Standard Time (UTC−7). Most of the US Mountain zone switches to MDT (UTC−6) in summer, but Arizona (except the Navajo Nation) stays on MST year-round.

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Full JST to MST conversion table

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

Daylight saving and how the gap changes

Around January MST is 16 hours behind JST. Around July it is 15 hours behind JST. That swing comes from one or both zones observing daylight saving on different schedules — the converter above always reflects the correct offset for the date you pick.

Frequently asked questions

Is MST ahead of or behind JST right now?
MST is currently 15 hours behind JST.
What is the current JST to MST time difference?
Right now the gap is 15 hours — MST is 15 hours behind JST.
Does the JST → MST offset change during the year?
Yes. Around January MST is 16 hours behind JST; around July it is 15 hours behind JST. The converter above always reflects the correct offset for the date you pick.
Does JST observe daylight saving time?
No — Japan Standard Time stays at a fixed UTC offset year-round.
Does MST observe daylight saving time?
MST is itself the standard-time form. Mountain Standard Time (US) is in force at UTC-7 through the winter months; outside that window the same zone is on MDT (UTC-6).
What time is 3 AM JST in MST?
3:00 AM JST is 12:00 PM (previous day) MST.
What time is 8 AM JST in MST?
8:00 AM JST is 5:00 PM (previous day) MST.
What time is 9 AM JST in MST?
9:00 AM JST is 6:00 PM (previous day) MST.
What time is 10 AM JST in MST?
10:00 AM JST is 7:00 PM (previous day) MST.
What time is 11 AM JST in MST?
11:00 AM JST is 8:00 PM (previous day) MST.
What time is 12 PM (noon) JST in MST?
12:00 PM JST is 9:00 PM (previous day) MST.
What time is 2 PM JST in MST?
2:00 PM JST is 11:00 PM (previous day) MST.
What time is 3 PM JST in MST?
3:00 PM JST is 12:00 AM MST.
What time is 4 PM JST in MST?
4:00 PM JST is 1:00 AM MST.
What time is 5 PM JST in MST?
5:00 PM JST is 2:00 AM MST.
What time is 9 PM JST in MST?
9:00 PM JST is 6:00 AM MST.
What time is 10 PM JST in MST?
10:00 PM JST is 7:00 AM MST.
When is the best time to schedule a call between JST and MST?
JST and MST have no direct 09:00–17:00 overlap on the same calendar day. Consider early-morning or late-evening slots on one side, or an asynchronous handoff.
What time zone does JST refer to?
JST refers to Japan Standard Time (IANA: Asia/Tokyo).
What time zone does MST refer to?
MST refers to Mountain Standard Time (US) (IANA: America/Denver).
Is MST on this page the same as other zones that share the letters "MST"?
MST is Mountain Standard Time (UTC−7). Most of the US Mountain zone switches to MDT (UTC−6) in summer, but Arizona (except the Navajo Nation) stays on MST year-round.

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