calculate age days

HTML

<input type="text" id="dateBirthday">
    
    <lable id="lblAge">Age in Days: </lable>

JavaScript

$(function() {

      var toDate = $("#dateBirthday").datepicker({

      defaultDate: "+1w",

      dateFormat: 'dd-M-yy',

      changeMonth: true,

      numberOfMonths: 1,
          maxDate: '+0d',

      onSelect: function(selectedDate)
   {

      var start = new Date();

      var end   = $('#dateBirthday').datepicker('getDate');
      var days   = Math.ceil((start - end)/1000/60/60/24);

       $('#lblAge').text(function(){
       return $(this).text()+' '+days;
       });
   }
  });
 });