$(document).ready(function(e) {
        'use strict';
    function calculation(){
    
   var date1 =new Date($('#start_date').val());
   

var date2 =new Date($('#end_date').val());
var timeDiff = Math.abs(date2.getTime() - date1.getTime());
var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24)); 
        $('#no_of_days').val(diffDays+1);
        
        }
        $('#end_date').change(calculation)


});
 