title: how to substract only working days from a specific date?
body: <p>assuming that we have a date of 18/06/2015 for example, and we want to substruct 5 days from it, (Saturday and Sunday not included).             </p>
  
  <p>I have thought to elaborate an algorihm with <code>DateAdd()</code>but i wanna know wether there is a function that that enables to do so</p>
  
  <p>thanks in advance </p>