var d = new Date();
//var a = d.toLocaleString() //2016/5/22 下午2:18:00
//var a = d.valueOf() //返回1971.1.1到现在的毫秒数
//var a = typeof(d.toString);
//var a = d.toLocaleTimeString() //下午2:17:43
//var a = d.toLocaleDateString(); //2016/5/22
//var a = d.toJSON() //2016-05-22T06:19:30.994Z
//var a = d.toUTCString() //Sun, 22 May 2016 06:20:58 GMT
//var a = d.toISOString() //2016-05-22T06:23:45.829Z
var setdocument.getElementById("demo").innerHTML = a;
<p id="demo"><p>