Exact·Age

Date Difference Calculator

How many days between two dates?

Enter a start date and an end date to get the exact number of days, weeks, months and years between them. Every leap year in the range is counted. Useful for deadlines, anniversaries, projects and contracts.

Counting days between dates

The number of days between two dates is the count of calendar days from the start date to the end date. By default this is the difference between the two dates — the number of nights — so 1 January to 2 January is one day. If you need to count both endpoints (for example, the total number of days a hotel booking or event spans), tick the include-both-days option to add one.

Leap years are handled automatically

Because the count is taken from the calendar itself rather than from a fixed 365-day year, every 29 February inside your date range is included. A span that crosses 29 February 2024, for instance, will be one day longer than the same span a year earlier.

What you can use it for

Common uses include counting down to a deadline, working out the length of a project or trip, measuring the gap between two events, or checking notice periods in a contract. The result is also shown in weeks and in years, months and days for convenience.

Frequently asked questions

Why does my result differ by one day from another tool?

Most likely because of the include-end-day setting. Counting only the gap between two dates gives one fewer day than counting both endpoints. Toggle the option to match the convention you need.

Can the end date be before the start date?

Yes — the calculator reports the magnitude of the gap regardless of order, and notes the direction.