方法一：

 // 获取当天的年月日

 new Date().getFullYear() + '-' + (new Date().getMonth() + 1) + '-' + new Date().getDate()；

 <form name="form1"> 

 <input type="text" name="test">

 </form>

 <script language="JavaScript">

 today=new Date();

 form1.test.value=today.getYear()+'年'+today.getMonth()+'月'+today.getDay()+'日';

 </script> 

 <br>

 方法二：

 --------------------------------------------------------------- 

 <input TYPE="text" id="myDate">

 <script langguage="JavaScript">

 <!--

 var now = new Date();

 myDate.value=new Date().getFullYear() + '-' + (new Date().getMonth() + 1) + '-' + new Date().getDate();

 //-->

 </script> 

 <br>

 方法三：

 --------------------------------------------------------------- 

 <script language="JavaScript">

 function time_rota()  //写当前日期的函数

 {

     var now = new Date();

     var h = now.getFullYear();

     var m = (now.getMonth() + 1>9) ? now.getMonth() + 1 : "0"+(now.getMonth() + 1);

     var s = (now.getDate()>9)  ? now.getDate()  : "0"+now.getDate();

     document.form1.Today.value = h+"年"+m+"月"+s+"日";

 }

 </script>

 <body onload="time_rota()"> 

 <form name=form1>

 <input name=Today>

 </form>