How to Calculate Business Days Between Two Dates
"Business days" (or working days) are the days a task actually progresses — normally Monday to Friday, excluding weekends and public holidays. Delivery windows, SLAs and payment terms are usually quoted in business days, so counting them correctly matters.
The method
- Count every day from the start date to the end date.
- Subtract the Saturdays and Sundays.
- Subtract any public holidays that fall on a weekday.
Worked example
From a Monday to the Friday of the following week is 11 calendar days. Remove the two weekends (4 days) and you get 10 business days. If a public holiday falls on one of those weekdays, it's 9.
Watch-outs
- Inclusive vs exclusive: decide whether the start day itself counts. "Within 5 business days" usually starts counting the next business day.
- Region matters: the weekend isn't Saturday–Sunday everywhere, and holidays differ by country and even state.
- Half-days and cut-off times aren't business-day math — track those separately.
Count them automatically
The Business Days Calculator counts weekdays between any two dates and lets you exclude the holidays that apply to you.
Scope
This guide assumes a Monday–Friday work week (the most common worldwide) with Saturday and Sunday as the weekend. Both the weekend definition and public holidays vary by country and region — the tool lets you exclude the specific holidays that apply to you.
Sources
Ready to do it?
Open the Business Days Calculator