js显示yyyy年mm日dd天 星期几 的格式日期

js代码：

     <script type="text/javascript">

         var today = new Date();

         var week; //存储星期几

         var date; //存储日期

         switch (today.getDay()) {

             case 0:

                 week = "星期日";

                 break;

             case 1:

                 week = "星期一";

                 break;

             case 2:

                 week = "星期三";

                 break;

             case 3:

                 week = "星期日";

                 break;

             case 4:

                 week = "星期四";

                 break;

             case 5:

                 week = "星期五";

                 break;

             case 6:

                 week = "星期六";

                 break;

             default:

                 week = "未知";

                 break;

         }

         date = (today.getFullYear()) + "年" + (today.getMonth() + 1) + "月" + today.getDate() + "日" + " ";

         document.write(date + week);  //将日期打印到body

     </script>