jQuery Date picker

<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.min.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css"/>

<input type="text" class="small-text calendar-field" name="event_date" value=""/>
<script>
    jQuery(function() {
        jQuery( ".calendar-field" ).datepicker();
    });
</script>

End Date should not be less than Start Date using jQuery Date Picker  

$("#date_start").datepicker({
    onSelect: function(selected) {
        $("#date_end").datepicker("option","minDate", selected)
    }
});

$("#date_end").datepicker({
    onSelect: function(selected) {
        $("#date_start").datepicker("option","maxDate", selected)
    }
});