How it works
The result counts elapsed calendar days and does not count the start date as a completed day. Reverse dates are rejected so the result stays easy to interpret.
Standard formula
end date − start dateWorked example
From January 1 to January 31 there are 30 elapsed days. Add one if you need an inclusive count of both endpoints.
Frequently Asked Questions
Is the count inclusive?
No. It counts elapsed days between the dates. For an inclusive count, add one.
Does it handle leap years?
Yes. Calendar calculations include February 29 when it exists.
Can I calculate months?
This page focuses on elapsed days; use Age Calculator for completed calendar years and months.
What dates are supported?
Enter valid Gregorian dates in the date fields.