Date.prototype.Format = function (fmt) { //author: meizz     var o = {        "M+": this.getMonth() + 1, //月份         "d+": this.getDate(), //日         "h+": this.getHours(), //小时         "m+": this.getMinutes(), //分         "s+": this.getSeconds(), //秒         "q+": Math.floor((this.getMonth() + 3) / 3), //季度         "S": this.getMilliseconds() //毫秒     };    if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));    for (var k in o)    if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));    return fmt;}		function daysJian(){  	  var date = new Date('2006-7-1 8:9:4.18');//获取当前时间  	  date.setDate(date.getDate()-1);//设置天数 -1 天  	   var time = date.Format("yyyy-MM-dd");  	   return time;		}	console.log(daysJian());

console.log("=====================")

console.log(new Date(1234567897789).Format("yyyy-MM-dd hh:mm:ss"))