JST to MDT Time Converter
Mountain Daylight Time (MDT) is currently 15 hours behind Japan Standard Time (JST). JST is UTC+9 and MDT is UTC-6. The table below converts every hour of the day between the two, and the call planner shows where working hours line up.
Best Time for a Call
Both sides are inside 9:00 AM to 5:00 PM office hours between 9:00 AM and 5:00 PM in JST, which is 9:00 AM to 5:00 PM in MDT.
Comparing more than two places? The Overlap Zones tool shows working hours for several cities on one grid.
Hour by Hour: JST to MDT
Rows marked office hours fall between 9:00 AM and 5:00 PM in both places. For a specific date, use the interactive converter.
Does the Difference Change During the Year?
JST and MDT are fixed offsets, so the difference between them never changes.
JST is UTC+9. Japan has no daylight saving, so this offset never changes.
MDT is UTC-6, the summer counterpart of MST, used from March to November.
Frequently Asked Questions
How many hours behind is MDT compared to JST?
MDT is currently 15 hours behind JST. JST and MDT are fixed offsets, so the difference between them never changes.
What time is 9:00 AM in JST in MDT?
9:00 AM in JST is 6:00 PM in MDT on the previous day.
What is the best time for a call between JST and MDT?
Both sides are inside 9:00 AM to 5:00 PM office hours between 9:00 AM and 5:00 PM in JST, which is 9:00 AM to 5:00 PM in MDT.