Are you referencing the number of days an employee has worked in a given period? Or are you simply wanting to calculate the number of days between the start and end date?
If you want to calculate the number of days from start to end that is simple enough. However, if you want to calculate that value and exclude weekends it would get trickier.
Check this post
This post may be of help as well
There is a way to get a list of dates using a plugin, but I can’t find the thread at the moment but do some digging and you should find it.
