how can i calculate business days in vbscript?

If you assume all Monday to Fridays are business days , you may use below examples

http://www.visualbasicscript.com/How-do-find-date-difference-for-only-business-days-m36903.aspx

http://stackoverflow.com/questions/22519605/add-3-or-5-days-to-now-excluding-weekendshttp://www.vbforums.com/showthread.php?683895-Calculating-WORKING-DAYS-(Mon-Fri)https://gist.github.com/sholsinger/921871

But if this thing involved with holidays , would get tricky