a simple jQuery based ticker

gistfile1.js

// a simple utility function for pretty printing
function pad(number, length) {
    var str = '' + number;
    while (str.length < length) {
        str = '0' + str;
    }
    return str;
}


var service_time = null,                                      // time on the server
    sync = 0,                                                 // the difference between server and client time
    party = new Date("Thu, 06 Mar 2012 17:00:00 GMT-0400"),   // time of the event
    times = [],                                               // used for "pretty" printing
    countdown_milliseconds = 0;                               // # of milliseconds between "now" and party

$("body").bind('$ready', function () {

    var $clock = $("#clock");                                 // jQuery reference to DOM node for the clock

    // build a clock...
    function tick() {

        // tick the clock, diff, subtract from event time
        countdown_milliseconds = party.getTime() - (sync + (new Date()).getTime());

        if (countdown_milliseconds > 0) {

            times = [];

            // step over days, hours, minutes, seconds and pick them off of the countdown
            $.each([(1000 * 60 * 60 * 24), (1000 * 60 * 60), (1000 * 60), 1000], function (i, unit) {
                times.push( pad( Math.floor(countdown_milliseconds / unit) , 2) );
                countdown_milliseconds %= unit;
            });

            // pretty "clock" printing
            $clock.html("-" + times.join(":"));

            // one-eigth of a second iterations
            setTimeout(tick, 125);

        } else {

            // hide the countdown, as we've just passed the threshold
            $clock.parent().hide();

        }
    };



    $.ajax({
        url: "/services/util/time_servlet.jsp?type=current_server_time",
        success: function (data) {

            console.log("data.currentServerTime", data.currentServerTime);
            console.log("new Date(server)", new Date(data.currentServerTime));
            console.log("new Date()      ", new Date());


            // store the difference between the client time and the server time
            sync = (new Date(data.currentServerTime)).getTime() - (new Date()).getTime();

            console.log("sync", sync);

            tick();
        },
        failure: function () {

            console.log('failure');

        },
        dataType: "json",
        cache: false
    });

});