This article provides an example of how JavaScript displays the current date and time in the browser title bar. The details are as follows:

Place this script in the head area:

<script language="JavaScript">
<!--
function resetIt() {
// Calculate Time
var timerID = null;
var timerRunning = false;
if(timerRunning)
  clearTimeout(timerID);
  timerRunning = false;
// getTime
var timeNow = new Date();
var hours = timeNow.getHours();
var minutes = timeNow.getMinutes();
var seconds = timeNow.getSeconds();
var timeValue = "" + ((hours >12) ? hours -12 :hours)
timeValue = ((timeValue <10)? "0":"") + timeValue
timeValue += ((minutes < 10) ? ":0" : ":") + minutes
timeValue += ((seconds < 10) ? ":0" : ":") + seconds
timeValue += (hours >= 12) ? " PM" : " AM"
timerID = setTimeout("resetIt()",100);
timerRunning = true;
// getDate
var dateNow = new Date();
var days = new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
var months = new Array('January','February','March','April','May','June','July','August','September','October','November','December');
var date = ((dateNow.getDate()<10) ? "0" : "")+ dateNow.getDate();
function y2k(number){return (number < 1000) ? number + 1900 : number;}
// compileIt
today = timeValue + " " + days[dateNow.getDay()] + " " +
        months[dateNow.getMonth()] + ", " +
        date + " " +
        (y2k(dateNow.getYear()));
  if(document.all || document.getElementById){ // Browser Check
   document.title = today.toString();
  }else{
   self.status = today.toString(); // Default to status.
  }
}
resetIt();
//-->
</script>

I hope this article has been helpful to your javascript programming.