Date Difference Calculator

Find the time between two dates

The Date Difference Calculator measures the span between any two dates, broken into years, months, and days, and also gives the total in days, weeks, and months. Pick a start and end date and the result appears instantly. It does not matter which date comes first — the tool always shows the positive difference.

Why calculate date differences?

Date math comes up constantly: figuring out the length of a project, the duration of a stay, the time between contract dates, someone's age, the gap between anniversaries, or the notice period before a deadline. Doing it by hand is error-prone because months have different lengths and leap years add a day. This calculator handles all of that for you.

How to use it

1. Select the start date.
2. Select the end date.
3. Read the difference in years/months/days, plus total days, weeks, and months.

Two ways to express a span

Format	Example	Best for
Years, months, days	2y 3m 14d	Ages, durations people relate to
Total days	835 days	Precise counting, billing, deadlines
Total weeks	119 weeks	Schedules and sprints

Accurate across months and leap years

The calculator counts complete years first, then months, then the remaining days, borrowing correctly from the previous month when needed — exactly how you would describe an age or duration. Because it works with real calendar dates, leap years and varying month lengths are handled automatically, so the result is always precise.

Common uses

• Calculating age or length of service.
• Measuring project or contract duration.
• Counting days for billing, rentals, or notice periods.
• Tracking time since or until a milestone.

Private and free

All calculations run in your browser, with nothing uploaded and no limits. Use it as often as you like, free.