Tokyo
Denver
Convert JST to MST
Japan Standard Time to Mountain Standard Time — Denver is 15 hours behind Tokyo
Quick Facts
Time Difference
-15 hours
JST Full Name
Japan Standard Time
MST Full Name
Mountain Standard Time
JST to MST Conversion Table
Related Conversions
About JST and MST Time Zones
JST (Japan Standard Time) is UTC+9 and covers cities like Tokyo, Osaka, Kyoto. MST (Mountain Standard Time) is UTC-7 and covers cities like Denver, Phoenix, Salt Lake City.
When it's 12:00 PM (noon) in Tokyo (JST), it's 9:00 PM in Denver (MST). The time difference between JST and MST is 15 hours — Denver is behind Tokyo.
With a 16-hour gap, scheduling overlap is very limited. Early morning in Tokyo (6–8 AM) corresponds to evening or late night in Denver.
Daylight Saving Time
MST observes Daylight Saving Time and becomes MDT (Mountain Daylight Time) during summer months, shifting clocks forward by 1 hour to UTC-6.
During DST transitions, the time difference between JST and MST may shift by ±1 hour. Always verify the current offset above for the most accurate conversion.
Use our world clock tool to compare Tokyo and Denver with a visual timeline, or browse more timezone conversions.
Frequently Asked Questions
What is the time difference between JST and MST?
Denver (MST) is 15 hours behind Tokyo (JST). The offset is -15 hours.
Is MST ahead or behind JST?
MST is 15 hours behind JST. JST is UTC+9 and MST is UTC-6.
When it's 12:00 PM in Tokyo, what time is it in Denver?
When it's 12:00 PM (noon) in Tokyo (JST), it's 9:00 PM in Denver (MST).
When it's 5:00 PM in Tokyo, what time is it in Denver?
When it's 5:00 PM in Tokyo (JST), it's 2:00 AM in Denver (MST).
Does MST change for Daylight Saving Time?
Yes. MST (Mountain Standard Time, UTC-7) becomes MDT (Mountain Daylight Time, UTC-6) in summer, shifting clocks forward 1 hour.