Calculators

Date Difference

Runs in your browser

Difference

days

Weeks

Months

Years

Hours

Minutes

Seconds

What is the Date Difference?

A date difference calculator counts the time between two dates in days, weeks, months, and years. It is used to count down to a deadline, work out a notice period, or measure how long something lasted.

It runs in your browser. To calculate a person's age specifically, use the Age Calculator.

How to use the Date Difference

Pick a start date and an end date. The difference appears instantly in days, with weeks, months, and years shown below.

Tick "Include the end day" if you want both the start and end dates counted - useful for booking nights, leave days, or event durations.

Tip: the order does not matter; the tool always shows the absolute difference.

Frequently asked questions

By default it counts the gap between the dates. Enable "Include the end day" to count both endpoints, which adds one day.
Weeks, months, and years are derived from the day count using average lengths (30.44 days per month, 365.25 per year), so they are approximate for long spans.
Yes. Any two valid dates work, in any order. The result is always the absolute difference.
No. The calculation happens entirely in your browser.