在JS中如何把毫秒转换成规定的日期时间格式实例

Date.prototype.toLocaleString = function() {
               return this.getFullYear() + "-" + (this.getMonth() + 1) + "-" + this.getDate() + " " + this.getHours() + ":" + this.getMinutes() + ":" + this.getSeconds();
            };

success:function(data){
          var Str="";  
          var length = data.length;
          for(var i=0;i'+data[i].roleName+''+data[i].remarks+''+data[i].createBy+''+data[i].createDate+''+data[i].updateBy+''+data[i].updateDate+''+data[i].status+'';
            Date.prototype.toLocaleString = function() {
               return this.getFullYear() + "-" + (this.getMonth() + 1) + "-" + this.getDate() + " " + this.getHours() + ":" + this.getMinutes() + ":" + this.getSeconds();
            };
            Str += "" +
             "" +
              "" +
                "" +
              "" +
             "" +
             "" +data[i].roleId+"" +
             "" +data[i].roleName+"" +
             "" +data[i].remarks+"" +
             "" +data[i].createBy+"" +
             "" +new Date(data[i].createDate).toLocaleString()+"" +
             "" +data[i].updateBy+"" +
             "" +new Date(data[i].updateDate).toLocaleString()+"" +
             "" +data[i].status+"" +
           "";
          }
          $("#rolelist").html(Str);
        }