JSFiddle - React, Tailwind, and code Playground

HTML

<input id="datepicker" />
<input id="weekNumber" />
<input id="dayName" />

JavaScript

jQuery(function () {
    jQuery('#datepicker').datepicker({
        onSelect: function (dateText, inst) {
            var d = new Date(dateText);
            jQuery('#weekNumber').val($.datepicker.iso8601Week(d));
            jQuery('#dayName').val($.datepicker.formatDate('DD', d));
        }
    });
});