简易js网页实时时钟日历

<script language="javascript">
function timeF(i){
if(i<10){
i="0"+i;
}
return i;
}
function showtime()
{
var today,hour,second,minute,year,month,date;
var strDate ;
today=new Date();
var n_day = today.getDay();
switch (n_day)
{
case 0:{
strDate = "星期日"
}break;
case 1:{
strDate = "星期一"
}break;
case 2:{
strDate ="星期二"
}break;
case 3:{
strDate = "星期三"
}break;
case 4:{
strDate = "星期四"
}break;
case 5:{
strDate = "星期五"
}break;
case 6:{
strDate = "星期六"
}break;
case 7:{
strDate = "星期日"
}break;
}
year = today.getFullYear();
month = today.getMonth()+1;
date = today.getDate();
hour = today.getHours();
minute =today.getMinutes();
second = today.getSeconds();
document.getElementById('time').innerHTML = year + "年" + month + "月" + date + "日  " + strDate +"  " + timeF(hour) + ":" + timeF(minute) + ":" + timeF(second); //显示时间
setTimeout("showtime();", 1000); //设定函数自动执行时间为 1000 ms(1 s)
}
</script>

<span id="time"></span><script language="javascript"> showtime();</script>