倒计时的实现

/* by liujun 2015-10-27 
* 倒计时的实现
*/
var fnTimeCountDown = function(d, o){
var f = {
        zero: function(n){
var n = parseInt(n, 10);
if(n > 0){
if(n <= 9){
                    n = "0" + n;    
                }
return String(n);
            }else{
return "00";    
            }
        },
        dv: function(){
            d = d || Date.UTC(2050, 0, 1); //如果未定义时间，则我们设定倒计时日期是2050年1月1日
var future = new Date(d), now = new Date();//取得将来时间对像和当前时间对像
//现在将来秒差值
var dur = Math.round((future.getTime() - now.getTime()) / 1000) + future.getTimezoneOffset() * 60, pms = {
                sec: "00",
                mini: "00",
                hour: "00",
                day: "00",
                month: "00",
                year: "0"
            };
if(dur > 0){
                pms.sec = f.zero(dur % 60);
                pms.mini = Math.floor((dur / 60)) > 0? f.zero(Math.floor((dur / 60)) % 60) : "00";
                pms.hour = Math.floor((dur / 3600)) > 0? f.zero(Math.floor((dur / 3600)) % 24) : "00";
                pms.day = Math.floor((dur / 86400)) > 0? f.zero(Math.floor((dur / 86400)) % 30) : "00";
//月份，以实际平均每月秒数计算
                pms.month = Math.floor((dur / 2629744)) > 0? f.zero(Math.floor((dur / 2629744)) % 12) : "00";
//年份，按按回归年365天5时48分46秒算
                pms.year = Math.floor((dur / 31556926)) > 0? Math.floor((dur / 31556926)) : "0";
            }
return pms;
        },
        ui: function(){
if(o.sec){
                o.sec.innerHTML = f.dv().sec;
            }
if(o.mini){
                o.mini.innerHTML = f.dv().mini;
            }
if(o.hour){
                o.hour.innerHTML = f.dv().hour;
            }
if(o.day){
                o.day.innerHTML = f.dv().day;
            }
if(o.month){
                o.month.innerHTML = f.dv().month;
            }
if(o.year){
                o.year.innerHTML = f.dv().year;
            }
            setTimeout(f.ui, 1000);
        }
    };    
    f.ui();
};




//调用
var zxx = {
    $: function(id){
return document.getElementById(id);    
    },
    futureDate: Date.UTC(2015, 12, 1, 10),
    obj: function(){
return {
            sec: zxx.$("sec"),
            mini: zxx.$("mini"),
            hour: zxx.$("hour"),
            day: zxx.$("day")
        }
    }
};
fnTimeCountDown(zxx.futureDate, zxx.obj());