<script type="text/javascript" src="script/jquery-1.8.3.min.js"></script>
<script>
$(document).ready(function () {
setInterval("startRequest()",1000);
});
function startRequest()
{
var date=new Date();

$("#timespan").text(date.toLocaleDateString()+" "+date.toLocaleTimeString());//<span id="timespan">
}
</script>