Date Difference
Calculate the exact number of days (and weeks) between any two dates — useful for deadlines, anniversaries, or project planning.
Counting the days between two dates by hand runs into the same category of problems as calculating age does — months have inconsistent lengths, leap years shift the count by a day in ways that are easy to forget, and manually counting across several months on a physical calendar is slow and genuinely error-prone once the gap stretches beyond a few weeks.
This is one of the more broadly useful calculations on this entire site precisely because it's not tied to any one specific use case — it's the same underlying math whether you're figuring out how many days until a deadline, how long a project ran, how many days pregnant someone is, or how far apart two historical events were. The calculation doesn't care what the dates represent; it just needs two dates and returns the gap between them.
Enter a start date and an end date, in either order, and this tool calculates the exact number of days between them, along with the same span broken out into years, months, and weeks where that framing is more useful. It's deliberately general-purpose — for date math with a specific added angle, like counting only business days or finding the day of the week for a date, the more specialized tools elsewhere on this site handle those narrower cases.
- Enter a start date.
- Enter an end date.
- Press "Calculate difference."
- See the result in both days and weeks.
Yes, the result shows the absolute number of days regardless of order.
It calculates the number of days between the two dates, not an inclusive day count.
Not in this version — this tool counts all calendar days.