Elegantno merenje vremena izvrsenja PHP procedura

http://php.net/manual/en/function.microtime.php

ou can use microtime and calculate the difference:

$time_pre = microtime(true);
exec(...);
$time_post = microtime(true);
$exec_time = $time_post - $time_pre;

http://stackoverflow.com/questions/8310487/start-and-stop-a-timer-php