//设置当前时间
SetTimeString = function () {
var s = document.getElementById('localedatetime');
var mydate = new Date();
s.innerHTML = mydate.toLocaleDateString() + ' ' + ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'][mydate.getDay()] + ' ' + mydate.toLocaleTimeString();
}
<div id="localedatetime">
<script type="text/javascript">
SetTimeString();
setInterval(SetTimeString, 1000);
</script>
<div>