Excel contains a function that helps you calculate the number of working days between 2 dates. It is called Networkdays. The function assumes a 5 days work week. To use the function, you need to activate an add-in called analysis toolpak. You can do this by going to the menu, tools, add-in and check on the box labelled “Analysis Toolpak”. You may require Microsoft Office installation disk to activate the add-in.
The function also allows you to add in holidays such that they are excluded if these holidays fall on weekday and are within the period for the calculation.