jQuery countdown counter

jquery.countdown.js

(function ($) {
    formatDuration = function(seconds) {
        var duration = '',
            days = Math.floor(seconds / 86400),
            hours = Math.floor(seconds / 3600) % 24,
            minutes = Math.floor(seconds / 60) % 60,
            seconds = seconds % 60;

        if (days)
            duration = days + ' day' + (days > 1 ? 's' : '') + ', ';
        
        duration += String("0" + hours).slice(-2) + ':' + String("0" + minutes).slice(-2) + ':' + String("0" + seconds).slice(-2);

        return duration;
    };
    
    $.fn.countdown = function() {
        this.each(function() {
            var self = $(this),
                remain = self.data('countdown-remain'),
                reached = self.data('countdown-reached') || '0',
                since = new Date().getTime(),
                countdown = function() {
                    var passed = Math.floor((new Date().getTime() - since) / 1000),
                        nowRemain = remain - passed;
                    self.text(nowRemain > 0 ? formatDuration(nowRemain) : reached);
                };
            countdown();
            self.data('countdown-interval', setInterval(countdown, 1000));
        });
    };
})(jQuery);