JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://jqueryui.com/themes/base/jquery.ui.all.css">
<div id="datepicker"></div>

CSS

.someDates a{
    color: red !important;
}

JavaScript

$(function() {

    $("#datepicker").datepicker({
        onChangeMonthYear: function(year, month, inst) {
            var bMonth = (new Date(this.value)).getMonth() != month - 1;
            var bYear = (new Date(this.value)).getFullYear() != year;
            if (bMonth || bYear) {
            setTimeout(function() {
                $('.ui-state-active').removeClass('ui-state-active');
            }, 5);
            }
        }
    });
});