How to use this in Wordpress?

[faysalhaque]

I've try this
(function($) {

$.datepicker._defaults.onAfterUpdate = null;

var datepicker__updateDatepicker = $.datepicker._updateDatepicker;
$.datepicker._updateDatepicker = function( inst ) {
datepicker__updateDatepicker.call( this, inst );

  var onAfterUpdate = this._get(inst, 'onAfterUpdate');
  if (onAfterUpdate)
     onAfterUpdate.apply((inst.input ? inst.input[0] : null),
        [(inst.input ? inst.input.val() : ''), inst]);

}

var cur = -1, prv = -1;
$('#jrange div')
.datepicker({
//numberOfMonths: 3,
changeMonth: true,
changeYear: true,
showButtonPanel: true,

        beforeShowDay: function ( date ) {
              return [true, ( (date.getTime() >= Math.min(prv, cur) && date.getTime() <= Math.max(prv, cur)) ? 'date-range-selected' : '')];
           },

        onSelect: function ( dateText, inst ) {
              var d1, d2;

              prv = cur;
              cur = (new Date(inst.selectedYear, inst.selectedMonth, inst.selectedDay)).getTime();
              if ( prv == -1 || prv == cur ) {
                 prv = cur;
                 $('#jrange input').val( dateText );
              } else {
                 d1 = $.datepicker.formatDate( 'mm/dd/yy', new Date(Math.min(prv,cur)), {} );
                 d2 = $.datepicker.formatDate( 'mm/dd/yy', new Date(Math.max(prv,cur)), {} );
                 $('#jrange input').val( d1+' - '+d2 );
              }
           },

        onChangeMonthYear: function ( year, month, inst ) {
              //prv = cur = -1;
           },

        onAfterUpdate: function ( inst ) {
              $('<button type="button" class="ui-datepicker-close ui-state-default ui-priority-primary ui-corner-all" data-handler="hide" data-event="click">Done</button>')
                 .appendTo($('#jrange div .ui-datepicker-buttonpane'))
                 .on('click', function () { $('#jrange div').hide(); });
           }
     })
  .position({
        my: 'left top',
        at: 'left bottom',
        of: $('#jrange input')
     })
  .hide();

$('#jrange input').on('focus', function (e) {
var v = this.value,
d;

     try {
        if ( v.indexOf(' - ') > -1 ) {
           d = v.split(' - ');

           prv = $.datepicker.parseDate( 'mm/dd/yy', d[0] ).getTime();
           cur = $.datepicker.parseDate( 'mm/dd/yy', d[1] ).getTime();

        } else if ( v.length > 0 ) {
           prv = cur = $.datepicker.parseDate( 'mm/dd/yy', v ).getTime();
        }
     } catch ( e ) {
        cur = prv = -1;
     }

     if ( cur > -1 )
        $('#jrange div').datepicker('setDate', new Date(cur));

     $('#jrange div').datepicker('refresh').show();
  });

})(jQuery);

But this doesn't work.