Get server time using JavaScript

Here's a way to get the server time using JavaScript.

    getServerTime(){
        var xmlHttp;
        try {
            //FF, Opera, Safari, Chrome
            xmlHttp = new XMLHttpRequest();
        }
        catch (err1) {
            //IE
            try {
                xmlHttp = new ActiveXObject('Msxml2.XMLHTTP');
            }
            catch (err2) {
                try {
                    xmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
                }
                catch (eerr3) {
                    //AJAX not supported, use CPU time.
                    alert("AJAX not supported");
                }
            }
        }
        xmlHttp.open('HEAD',window.location.href.toString(),false);
        xmlHttp.setRequestHeader("Content-Type", "text/html");
        xmlHttp.send('');
        return xmlHttp.getResponseHeader("Date");
    }