NETWORKDAYS is a function in the Analysis Toolpak that returns the number of working days between two days. If you need to find a day that is a specified number of working days away, then use the WORKDAY function (or its alternative).
This example shows the syntax for WORKDAY, but doesn’t use the optional holidays argument. The other two formulas are B3: a straight subtraction of two days and D3: Frank Kabel’s alternative array formula.
To find a day that’s a number of days away from a start date, but returning Friday if the result is Saturday and returning Monday if the result is Sunday, you can use a formula like this:
This computes the day of the week number and uses the CHOOSE function to add a day if WEEKDAY returns 1 (Sunday to Monday) and subtract a day if WEEKDAY returns 7 (Saturday to Friday).