JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="datepicker" />

JavaScript

var holidayArray2013 = [
    new Date('October 3, 2013 00:00:00 GMT+0200').valueOf(),
    new Date('December 25, 2013 00:00:00 GMT+0100').valueOf(),
    new Date('December 26, 2013 00:00:00 GMT+0100').valueOf() ];

$("#datepicker").datepicker().change(function() {
    var DateOfOrder = $('#datepicker').datepicker('getDate').valueOf();
    if ($.inArray(DateOfOrder, holidayArray2013) > -1) {
        console.log("is holiday");
    }
});