Date Duration Calculator
Count days between dates or add and subtract days from a date for deadlines, trips, habits, billing windows, and planning.
Days between dates
Add or subtract days
Result
Pick dates or add days to a date.
Date counting tips
Use exclusive counting for elapsed time between two dates. Use include end date when each calendar day in a range should count. For deadlines, the add/subtract section is often faster than manually counting on a calendar.
Date planning examples
- Project timeline — Count working-window days between milestones.
- Event countdown — Calculate days left until a deadline.
- Follow-up date — Add 30, 60, or 90 days to a base date.
Privacy note: entries are handled in your browser, and the useful result can be copied, printed, or downloaded when available.
Frequently asked questions
Can I include the end date?
Yes. Turn on include end date when you want both the start and end dates counted, such as for trips or challenges.
Does this tool save my entries?
No. The calculation runs in your browser, and your entries stay on your computer unless you copy the result.
Does this account for leap years?
Yes. The calculation uses actual calendar dates, so leap days are included when they fall in the selected range.