Date对象常见使用

内置对象Date的常见用法

一、倒计时天数

window.οnlοad=function(){
        var a=new Date();
        var b=new Date("2016,6,7");
        var lefttime=Math.ceil((b.getTime()-a.getTime())/(24*60*60*1000));
        document.getElementById('show').innerHTML=lefttime;
    };

二、抢时限

 function showTime(){
        var a=new Date();
        var b=new Date("2016/6/7,12:20:12");
        var lefttime=parseInt((b.getTime()-a.getTime())/1000);//秒
        var d=parseInt(lefttime/(24*60*60));//天
        var h=parseInt(lefttime/(60*60)%24);//时
        var m=parseInt(lefttime/60%60);
        var s=parseInt(lefttime%60);
        document.getElementById('show').innerHTML=d+'天'+h+'小时'+m+'分'+s+'秒';
        setInterval(showTime,500);

    }

三、显示时间

function check(i){
                if (i<10) {
                    return '0'+i;
                } else {
                    return i;
                }
            }

        function showTime(){
            var myDate=new Date();
            var year=myDate.getFullYear();
            var month=myDate.getMonth()+1;
            var date=myDate.getDate();//日
            var w=myDate.getDay();//星期
            var h=myDate.getHours();
            var m=myDate.getMinutes();
            var s=myDate.getSeconds();
            var week=new Array(7);
            m=check(m);
            h=check(h);
            s=check(s);
            week[0]="星期日";
            week[1]="星期一";
            week[2]="星期二";
            week[3]="星期三";
            week[4]="星期四";
            week[5]="星期五";
            week[6]="星期六";
            document.getElementById('show').innerHTML=year+'年'+month+'月'+date+'日'+week[w]+h+':'+m+':'+s;
            setTimeout(showTime,500);


        }