function formatTime(val) {

var re = /-?\d+/;

var m = re.exec(val);

var d = new Date(parseInt(m[0]));

console.log(d)

// 按【2012-02-13 09:09:09】的格式返回日期 

// "yyyy-MM-dd hh:mm:ss"

// 按【2012-02-13】的格式返回日期

return d.format("yyyy-MM-dd");

}

Date.prototype.format = function (format) //author: meizz

{

var o = {

"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 o) if (new RegExp("(" + k + ")").test(format))

format = format.replace(RegExp.$1,

RegExp.$1.length == 1 ? o[k] :

("00" + o[k]).substr(("" + o[k]).length));

return format;

}

两种方法参考http://www.jb51.net/article/91600.htm