//Author: meizz
"use strict";

Date.prototype.format = function (format)
{
    var obj = {
        "M+": this.getMonth() + 1,                          //month
        "d+": this.getDate(),                               //day
        "h+": this.getHours(),                              //hour
        "m+": this.getMinutes(),                            //minute
        "s+": this.getSeconds(),                            //second
        "q+": Math.floor((this.getMonth() + 3) / 3),        //quarter
        "S": this.getMilliseconds()                         //millisecond
    };

    if (/(y+)/.test(format)) format = format.replace(RegExp.$1,
        (this.getFullYear() + "").substr(4 - RegExp.$1.length));
    for (var k in obj)
        if (new RegExp("(" + k + ")").test(format))
            format = format.replace(RegExp.$1,
                RegExp.$1.length == 1 ? obj[k] :
                ("00" + obj[k]).substr(("" + obj[k]).length));
    return format;
};

alert(new Date().format("yyyy-MM-dd"));
alert(new Date("january 12 2008 11:12:30").format("yyyy-MM-dd hh:mm:ss"));