working days calculation

dears,

good day!! 

i have a file called dim date it has a culomns called G_date where it shows the date from 12/29/2008 till 5/13/2029 

how can i calculate the working days if holidays are fri and sat 

i have another culomn called vacation where 1 vacation  and blank working days 

i need to calculate working days in each moth can you help please ??