<?php
$starttime = explode(' ', microtime());
$starttime = $starttime[1] + $starttime[0];
?>
<html>
<head>
<title>TEST</title>
<meta http-equiv="content-type" content="text/html; charset=windows-1251" />
</head>
<body>
... бла бла бла
</body>
</html>
<?php
$mtime = explode(' ', microtime());
$totaltime = $mtime[0] + $mtime[1] - $starttime;
printf('Генерирано за %.3f секунди...', $totaltime);
?>