倒计时

    function ShowCountDown(year,month,day,hours,mintes,seconds,divname) {
        function c(xx) {
            if(xx<0){
                return 0
            }else{
                return (xx<10)?'0'+xx:xx;
            }
        }
        var now = new Date();
        var endDate = new Date(year, month-1, day,hours,mintes,seconds);
        var leftTime=endDate.getTime()-now.getTime();
        var leftsecond = parseInt(leftTime/1000);
//var day1=parseInt(leftsecond/(24*60*60*6));
        var day1=Math.floor(leftsecond/(60*60*24));
        var hour=Math.floor((leftsecond-day1*24*60*60)/3600);
        var minute=Math.floor((leftsecond-day1*24*60*60-hour*3600)/60);
        var second=Math.floor(leftsecond-day1*24*60*60-hour*3600-minute*60);
        var cc = document.getElementById(divname);
        function f(day1,time) {/*负数时间*/
                if(day1<0){
                    return 0
                }else{
                    return (time<10)?'0'+time:time;
                }
        }
        cc.innerHTML = '<p class="day">'+c(day1)+'天</p>'+'<p class="time">'+f(day1,hour)+"小时"+f(day1,minute)+"分"+f(day1,second)+"秒"+'</p>';
    }

//调用

var interval = 1000;
    window.setInterval(function(){ShowCountDown(2018,1,15,17,00,00,'time1');}, interval);