title: Add 4 weekdays to the WooCommerce order_date
body: <p>I want the WooCommerce packing slip to show a pickup date for our staff.  I can't seem to get it to pull from the <code>order_date</code>.  It just pulls from today's date.  If I print the packing slip a day after the order was placed, it doesn't show the correct date.  </p>
  
  <p>I feel like I have tried everything to add <code>order_date</code> to the string but I can't figure it out.</p>
  
  <p>This is what I have used.  </p>
  
  <pre><code>$var=date('"l, F, jS"', strtotime( '+ 4 weekdays'));
  echo $vaI; 
  </code></pre>
  
  <p>I want it to just show 4 weekdays from the order date. Not from the date I print the packing slip.</p>