php count time since script start code example

Example 1: php time a script

//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';

Example 2: php check how much time each instruction takes to complete

$start = microtime(true);
while (...) {

}
$time_elapsed_secs = microtime(true) - $start;