Japan to MDT
-15hJapan
JSTSOURCEMDT
MDTGreen rows indicate typical business hours (9 AM - 5 PM)
JST and MDT on the World Map
The map below highlights the JST (Japan Standard Time) and MDT (Mountain Daylight Time) timezone regions across the globe.
JST – Japan Standard Time
UTC+09:00Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.
- •Japan does not observe daylight saving time.
- •Tokyo is the most populous metropolitan area in the world.
- •The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
- •JST is 14 hours ahead of EST and 9 hours ahead of GMT.
MDT – Mountain Daylight Time
UTC-06:00Mountain Daylight Time (MDT) is the daylight saving offset in the Mountain Time Zone, 6 hours behind UTC.
- •MDT shares the same offset as CST (UTC-06:00).
- •Arizona does not switch to MDT, remaining on MST.
Everything You Need to Know About Japan and MDT Time
Japan runs on Japan Standard Time (JST) at UTC+09:00. MDT runs on Mountain Daylight Time (MDT) at UTC-06:00. That puts Japan 15 hours behind MDT — a difference of -15h at the current offsets.
In practice, when it is 9:00 AM in Japan it is 6:00 PM in MDT on the previous day. Midnight in Japan is 9:00 AM in MDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Japan to MDT time conversion table
| Japan (JST) | MDT (MDT) | Day |
|---|---|---|
| 12:00 AM | 9:00 AM | previous day |
| 6:00 AM | 3:00 PM | previous day |
| 7:00 AM | 4:00 PM | previous day |
| 8:00 AM | 5:00 PM | previous day |
| 9:00 AM | 6:00 PM | previous day |
| 12:00 PM | 9:00 PM | previous day |
| 3:00 PM | 12:00 AM | same day |
| 5:00 PM | 2:00 AM | same day |
| 6:00 PM | 3:00 AM | same day |
| 9:00 PM | 6:00 AM | same day |
Why people convert Japan to MDT time
- Scheduling a call from Japan to MDT: a 10:00 AM start in Japan lands at 7:00 PM in MDT the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -15h gap: Japan and MDT have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in MDT is 6:00 PM in Japan.
- Coordinating a Japan-based team with MDT contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM JST" is unambiguous; "3 PM" across a -15h gap is not.
- With a -15h gap there is no shared 9-to-5 window, so alternate the early start: one week Japan takes the early slot, the next week MDT does.
About JST (Japan Standard Time)
Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.
About MDT (Mountain Daylight Time)
Mountain Daylight Time (MDT) is observed during summer months in the Mountain Time Zone, except in Arizona which stays on MST year-round. MDT aligns with Central Standard Time (CST) at UTC-06:00.
Best time to call between Japan and MDT
With a -15h offset there is no overlap inside a normal 9 AM – 5 PM day. MDT opens at 9:00 AM MDT, which is 6:00 PM in Japan, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Japan and MDT have no shared working hours because of the -15h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Japan is 15 hours behind MDT (JST UTC+09:00 → MDT UTC-06:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Japan
Does not observe DST
MDT
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between Japan and MDT?
Japan (JST, UTC+09:00) is 15 hours behind MDT (MDT, UTC-06:00). The gap is currently -15h.
How do I convert Japan time to MDT time?
Add -15h to Japan local time. For example, 9:00 AM in Japan is 6:00 PM in MDT (previous day).
What time is it in MDT right now?
MDT uses MDT at UTC-06:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -15h offset from Japan.
What is the best time to call MDT from Japan?
There is no shared working-hours window because of the -15h gap. The closest option is 1:00 PM in Japan, which is 10:00 PM in MDT.
Which is behind, Japan or MDT?
Japan is 15 hours behind MDT. When it is 12:00 PM in Japan it is 9:00 PM in MDT.
Do Japan and MDT use different time zones?
Japan (Japan) uses JST at UTC+09:00, while MDT uses MDT at UTC-06:00. The IANA identifiers are Asia/Tokyo and America/Denver.
Does daylight saving time affect the Japan–MDT difference?
Neither zone observes daylight saving time, so the -15h offset between Japan and MDT is fixed all year.
Which other cities share Japan's time zone?
JST also covers Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Kobe, Fukuoka and 1 more.
Which countries use JST, Japan's zone?
JST is used in Japan.
Is there a day difference between Japan and MDT?
Sometimes. The -15h gap is large enough that 8:00 PM or later in Japan already falls on the in MDT.
What is the time difference between Japan and MDT?
MDT is -15h from Japan.
What timezone is Japan in?
Japan operates on its local timezone.
What timezone is MDT in?
MDT operates on its local timezone.
Which countries use JST (Japan Standard Time)?
JST is used in Japan.
Does JST observe daylight saving time?
No, JST does not observe daylight saving time and remains at UTC+09:00 year-round.
What are some interesting facts about JST?
Japan does not observe daylight saving time. Tokyo is the most populous metropolitan area in the world.
Which cities are in the MDT timezone?
Major cities in the MDT timezone include Denver, Calgary, Edmonton, Salt Lake City, Boise.
What is the UTC offset for MDT?
Mountain Daylight Time (MDT) is at UTC-06:00. During daylight saving time, it shifts to MST.
What should I know about the MDT timezone?
MDT shares the same offset as CST (UTC-06:00). Arizona does not switch to MDT, remaining on MST.
When is it midnight in Japan, what time is it in MDT?
When it is 12:00 AM (midnight) in Japan (JST), it is -15h later in MDT (MDT).
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See every conversion from Japan →·See every conversion from MDT →