<?php
header('Location: login.php'); // redirects the user instantaneously.
exit;
?>

<?php
header('refresh: 10; url=login.php'); // redirect the user after 10 seconds
#exit; // note that exit is not required, HTML can be displayed.
?>

<p>You will be redirected in <span id="counter">10</span> second(s).</p>
<script type="text/javascript">
function countdown() {
    var i = document.getElementById('counter');
    if (parseInt(i.innerHTML)<=0) {
        location.href = 'login.php';
    }
    i.innerHTML = parseInt(i.innerHTML)-1;
}
setInterval(function(){ countdown(); },1000);
</script>

หรือ ใช้  javascript

var counter = 10;
setInterval(function() {
    counter--;
    if(counter < 0) {
        window.location = 'login.php';
    } else {
        document.getElementById("count").innerHTML = counter;
         }
}, 1000);​

หรือ

<b><span id="count">10</span> Seconds</b>

var count = 10;
function decrement() {
    count--;
    if(count == 0) {
        window.location = 'login.php';
    }
    else {
        document.findElementById("count").innerHTML = "" + count;
        setTimeout("decrement", 1000);
    }
}
setTimeout("decrement", 1000);

https://stackoverflow.com/questions/12498209/redirect-10-second-countdown