Days Between Dates Calculator
Count the calendar days, weeks, and business days between any two dates.
Runs entirely in your browser. Your dates are never uploaded anywhere.
How to use this tool
Pick a start date and an end date using the two date fields, then press Calculate. The days between dates calculator shows the total number of calendar days, the equivalent in weeks, and the number of business days (Monday through Friday) in the range. If you want to know the days until a future date, leave the start date on today and set the end date to your target. Tick the "Include the end date" box when you want the final day counted as well, which is common for billing periods and event countdowns. Use Copy result to grab the summary, or the today shortcut to jump the start date to the current day.
How it works
The tool reads both dates with the browser's built-in Date object, then subtracts them at midnight so partial hours never throw off the count. Dividing the difference in milliseconds by the number of milliseconds in a day gives whole calendar days. To count business days, it steps through each date in the range and adds one for every day that is not a Saturday or Sunday. This is a simple weekday count and does not subtract public holidays, which vary by country and state.
A real example
Say the start date is March 1, 2026 and the end date is March 15, 2026. Subtracting the two gives 14 calendar days, which is exactly 2 weeks. Within that span there are 10 weekdays, so the tool reports 10 business days. If you tick "Include the end date", the calendar total becomes 15 days because the final day is now counted too.
Common questions
Does this count business days only?
No. It shows total calendar days, weeks, and business days all at once. Business days here means Monday through Friday and do not exclude public holidays, which differ by region.
How do I find the days until a date?
Press "Set start to today" so the start date is the current day, then choose your target date as the end date. The total days value is your countdown.
What if the end date is before the start date?
The tool uses the absolute difference, so the count is always a positive number no matter which date you enter first.
Why does the count change when I include the end date?
By default the result is the gap between the two dates. Including the end date adds one more day, which matches how many billing systems and event countdowns count a range.
Are leap years handled correctly?
Yes. The calculation works on the actual calendar dates through the browser's Date object, so February 29 in a leap year is counted just like any other day.