To count business days between two dates, count the days in the range and drop every Saturday and Sunday, which leaves the Monday-to-Friday total. A full working week is five business days. The business days calculator does this for any range and can also add a number of business days to a date.
Most of the work is just deciding what counts as a working day, so here is the method in full.
What counts as a business day
In the simple, widely used model, business days are Monday to Friday. Saturday and Sunday are non-working. So a span from a Monday to the following Monday covers two weekends’ worth of removal and lands on five business days for each full week.
This model does not know about public holidays, because those differ by country and region. If your range includes a public holiday that your workplace observes, count the business days first and then subtract the holidays.
How the end day affects the total
As with any date range, whether you count the final day changes the total by one. For elapsed working time, the start day usually counts and the end day does not. For a span where the last working day is also “used”, you include it.
For example, Monday to the same week’s Friday is four business days if you count elapsed days from Monday, or five if both Monday and Friday count. The business days calculator has an include-end-day toggle so you can match how your task is measured.
Adding business days to a date
The reverse question is just as common: if something takes ten working days, when is it due? To add business days, step forward from the start date one day at a time and count only the weekdays until you reach the number you need.
Because weekends are skipped, adding one business day to a Friday lands on Monday, and adding five business days to a Monday lands on the following Monday. Switch the business days calculator to its add mode to get the date directly.
Where this comes up
Working-day counts drive a lot of everyday planning:
- Delivery and lead times, quoted in working days that skip the weekend.
- Service levels and turnaround, where a ticket is due a set number of working days out.
- Payroll and invoicing, where you count the weekdays in a period.
To count plain calendar days instead, see how many days between two dates, or open the business days calculator to try both modes.