Dynamic Server Time

As I understand there is no way I can get dynamic server time in IE with settimeout() in script.. I found this example: function timeExam(){ $.ajax({ url : 'inc/clock.php

Solution 1:

What your script does is poll a script on your server at inc/clock.php and replace your #clock_time element's contents with the output from the script (roughly) every second. This should work, provided you have a element with id clock_element and a script at yoursite.tld/inc/clock.php

However, I disagree to constantly poll the server for it's current time. It should suffice to sync time only once to your webserver. Beside some minor differences this should keep your clocks synced well enough for a good while. If your webapp will run more than a couple of hours or days you should periodicly resync your clock (once a day or a week should do).

Use a Date object to keep track of the servertime on your client. Simply create a Date object from the output of clock.php (a valid date output as prerequisite) and update your clock_element periodicly (like every second) according to the time delta from when you synced your clock with the remote server.

Here some rough code, not tested, propably some syntax errors, but briefly shows what you should do:

functionsetupServerClock( clock_element, remote_time_url, remote_update_interval, local_update_interval ) {
    var w = window;
    // client time on resyncvar ct = newDate();
    // server time on resyncvar st = newDate();
    // setup resync
    w.setInterval( function() {
        jQuery.ajax( {
            url: remote_time_url,
            success: function (data) {
                ct = newDate();
                st = newDate(data);
            }
        });
    }, remote_update_interval);
    // setup local clock display
    w.setInterval( function() {
        // the time passed on our local machine since the last resyncvar delta = newDate() - ct;
        // we assume the same time passed at the server// (yeah, I know, spacetime might not be the same at the servers // place and off the shelve clocks are pretty inaccurate)var clock = st - 0 + delta; // - 0 to convert to microsecond timestampjQuery(clock_element).html(newDate(clock));
    }, local_update_interval);
}

Call it with something like:

setupServerClock( jQuery('#clock_element'), 'inc/clock.php', 1000 * 60 * 60, 1000 );

This will setup the clock to be written to #clock_element, using the value returned from yourdomain.tld/inc/clock.php, resync the clock every hour and update the local representation of the clock every second.

Oh and if that periodical resync indeed brings up "jumps" in the clock you could think about simply giving the user feedback, that his clock was updated, eg like this

    w.setInterval( function() {
        jQuery(clock_element).html('resyncing clock...');
        jQuery.ajax( {
            url: remote_time_url,
            success: function (data) {
                ct = newDate();
                st = newDate(data);
            }
        });
    }, remote_update_interval);

Solution 2:

Since you're using jQuery:

$(function() {
  var updateSeconds = 60;
  functionupdateClock() {
    $.ajax({
      url : "inc/clock.php",
      success : function (data) {
        $("#clock_time").html(data);
        setTimeout(updateClock, updateSeconds * 1000);
      }
    });
  }
  setTimeout(updateClock, updateSeconds * 1000);
});

Change "updateSeconds" however you want.

I did this with setTimeout instead of setInterval because it's a little safer. If there's a server problem, this one won't pile up doomed HTTP requests over and over again, because it doesn't set up a new update until the current one succeeds.