Created in X seconds

I see that this is already done but how?
Anyone can help me?

Do that:
on top of your header.php add:

function getmicrotime(){
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
$chrono1 = getmicrotime();

and at the bottom of your footer.php add:

$chrono2 = getmicrotime();
echo Created in '.number_format(($chrono2 - $chrono1),5).' seconds.';

that's it

Marc

Thank you, it worked!
I knew it would be something simple, but couldn't figure it out.