JST to EDT Time Converter
Eastern Daylight Time (EDT) is currently 13 hours behind Japan Standard Time (JST). JST is UTC+9 and EDT is UTC-4. 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
There is no overlap between 9:00 AM and 5:00 PM office hours in these two zones. Stretching to early mornings and evenings, the workable window runs from 8:00 PM to 9:00 PM in JST, which is 7:00 AM to 8:00 AM in EDT. One side ends up outside normal hours, so alternating who takes the awkward slot is a fair way to handle recurring calls.
Comparing more than two places? The Overlap Zones tool shows working hours for several cities on one grid.
Hour by Hour: JST to EDT
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 EDT are fixed offsets, so the difference between them never changes.
JST is UTC+9. Japan has no daylight saving, so this offset never changes.
EDT is UTC-4, the summer counterpart of EST. Eastern North America uses it from March to November.
Frequently Asked Questions
How many hours behind is EDT compared to JST?
EDT is currently 13 hours behind JST. JST and EDT are fixed offsets, so the difference between them never changes.
What time is 9:00 AM in JST in EDT?
9:00 AM in JST is 8:00 PM in EDT on the previous day.
What is the best time for a call between JST and EDT?
There is no overlap between 9:00 AM and 5:00 PM office hours in these two zones. Stretching to early mornings and evenings, the workable window runs from 8:00 PM to 9:00 PM in JST, which is 7:00 AM to 8:00 AM in EDT. One side ends up outside normal hours, so alternating who takes the awkward slot is a fair way to handle recurring calls.