title: Add days to a date from one bootstrap datetimepicker and mirror to another?
body: <p>I'm using the Bootstrap Date Time Picker (<a href="http://www.malot.fr/bootstrap-datetimepicker/" rel="nofollow">http://www.malot.fr/bootstrap-datetimepicker/</a>) to allow a user to select a date and time in one field and then need to recommend a date 21 days following the initially selected date/time in a 2nd field.</p>
  
  <p>I'm wondering how I would go about 'mirroring' one field to another like this but add X days? There is a feature documented that allows mirroring but I don't see how to use this to add days (<a href="http://www.malot.fr/bootstrap-datetimepicker/demo.php" rel="nofollow">http://www.malot.fr/bootstrap-datetimepicker/demo.php</a> - see mirror field demo).</p>
  
  <p>i.e. take the date selected using the datetimepicker for field A and mirror it to field B 'but' add 21 days to the date and use that as the default date for the B field?</p>