Date.prototype.format = function(format){
   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;
  }

 

调用：

var time=new Date(d.regday);
 var nowtime=time.format("yyyy-MM-dd")