Se vuoi percorrere quella strada, tanto valeva usare:

// file http://remotesite/time.php
Codice PHP:
<?php echo serialize(microtime(true)); ?>
// file http://localsite/time.php
Codice PHP:
<?php
$time 
unserialize(file_get_contents('http://remotesite/time.php'));
var_dump($time);
?>