calculate number days between dates less Sat and Sun

I am trying to caluclate the number of days between two dates (less Saturday and Sunday). For example, say I have days as follows:

Wed, Aug 1
Thur, Aug 2
Fri, Aug 3
Sat, Aug 4
Sun, Aug 5
Mon, Aug 6
Tue, Aug 7

So if I want to calculate the number of days between Aug 1 and Aug 7, the desired result is 4 days. Thank you.