Jquery Ui date time picker

Question

I am using jquery date time picker and using start date and end date.

When selecting same date for start date and end date I do not want it to allow the end date time to be less than start date time. How would I adjust my code?

$( "#fdate" ).datetimepicker({
     dateFormat: 'yy-mm-dd',timeFormat: 'HH:mm:ss',
        onClose: function( selectedDate ) {
        $( "#tdate" ).datetimepicker( "option", "minDate", selectedDate );
  }
  }).attr('readonly', 'readonly');
     $( "#tdate" ).datetimepicker({dateFormat: 'yy-mm-dd',timeFormat: 'HH:mm:ss',
  onClose: function( selectedDate ) {
     $( "#fdate" ).datetimepicker( "option", "maxDate", selectedDate );
  }
  }).attr('readonly', 'readonly');
});

here fdate is start date and tdate is end date and here is Fiddle of the issue