Days Between Dates Calculator

This free date duration calculator helps you find the exact number of days between any two dates. Whether you're counting down to a vacation, tracking a project deadline, or calculating how long since an event, here's how to get started:

1. Pick your start date — click the date field or use the "Set Start to Today" button for quick setup.
2. Pick your end date — select any future or past date. Use quick buttons like "+30 Days" or "+1 Year" for common ranges.
3. Adjust options — toggle "Include start date" or "Include end date" to control inclusive counting. Enable "Business days only" to exclude weekends.
4. Click Calculate — instantly see results in days, weeks, months, years, hours, minutes, and seconds.

Use the "Swap Dates" button to quickly reverse the date range. All calculations happen instantly in your browser — no data is sent to any server.

The calculator computes the absolute difference between your two dates in milliseconds, then converts that into days, weeks, months, and years. It uses the Gregorian calendar and accounts for varying month lengths and leap years when computing month/year breakdowns.

Business day counting excludes Saturdays and Sundays from the total. The system is designed to support holiday exclusions in the future — for now, only weekends are excluded.

The "include start/end date" options adjust the counting method. By default, the calculator counts the gap between dates (e.g., January 1 to January 3 = 2 days). When you include the start or end date, it adds one day to create an inclusive count.