PHP Time Limit:

PHP
set_time_limit(300);max_execution_time = 300;//place this before any script you want to calculate time
$time_start = microtime(true); 

//sample script
for($i=0; $i<1000; $i++){
 //do anything
}

$time_end = microtime(true);
$execution_time = ($time_end - $time_start);
echo '<b>Total Execution Time:</b> '.($execution_time*1000).'Milliseconds';

Source

Also in PHP: