Date Calculator
Measure the distance between any two dates. Get the total in days, weeks, months and years, count only business days, and choose whether the end day is included.
Choose a start date and an end date to see the full breakdown.
How the date calculator works
The core question, how many days between two dates, comes down to counting midnights. The calculator strips the time of day from each date and measures the number of whole days from the start to the end. That keeps the answer stable no matter what hour you open the page, and it means daylight saving changes never throw the count off.
By default the end day is excluded, which is the convention most people expect: the gap from Monday to Wednesday is two days. When you need both endpoints counted, for example when billing for a stay that covers the final day, switch on the include-end-day option and the total goes up by one.
Weeks, months and years
Weeks are simply the day count divided by seven, shown with a couple of decimals so partial weeks are clear. The calendar breakdown into years, months and days uses natural borrowing, counting whole years first, then whole months, then the leftover days. This matches how a duration is normally spoken, such as 3 years, 4 months and 12 days, rather than a raw fraction.
Business days and holidays
The business-days figure counts Monday through Friday and skips every Saturday and Sunday in the range. It is ideal for estimating working time on a project or a delivery window. Public holidays are left in, because holiday calendars vary widely between countries and regions, so treat the business-day count as the working-week baseline and subtract any local holidays yourself.
Leap years and edge cases
Because the tool counts real calendar days, a range that crosses February 29 in a leap year is automatically one day longer than the same span in a common year. If you reverse the two dates, the result is shown as a positive span so it stays readable, and the calendar breakdown always describes the true gap between them.
Frequently asked questions
How do I count the number of days between two dates?
Count the whole midnights that separate the two calendar dates. By default the calculator excludes the end day, so March 1 to March 3 is two days. Tick the include-end-day option to count both endpoints, which gives three days for the same range.
What is the difference between calendar days and business days?
Calendar days count every day, including weekends. Business days count Monday through Friday only. The tool reports both. Public holidays are not removed because they differ from country to country.
Does the calculator handle leap years?
Yes. Because it counts real calendar days, any February 29 inside the range is included automatically, so a span that crosses a leap day is one day longer than the same span in a common year.
Can the end date be before the start date?
Yes. If you enter an end date earlier than the start date, the tool still shows the size of the gap as a positive number of days so the result stays easy to read.
How are months and years counted?
The calendar breakdown uses natural borrowing. It counts whole years first, then whole months, then leftover days, the same way you would state a duration out loud, such as 1 year, 2 months and 5 days.
Related tools
Keep the date math going with the rest of the toolkit.