Edit in JSFiddle

$(function() {
     $("input.questionDate").datepicker({
            dateFormat: 'mm/dd/yy'
        });


        $("input.questionDate").each(function(){
            var currentValue = $(this).val();
            if(currentValue)
                $(this).datepicker('setDate',new Date(currentValue));

        });
        $("input.questionDate").keydown(function(event) {
            if(event.keyCode != 8){
                event.preventDefault();
            }
        });
    
});

Start Date: <input class="questionDate" value=" 05/16/2015 ">
<br>
End Date: <input class="questionDate" value=" 05/31/2015 "><br>