function startTime() {
    $mtime = microtime();
    $mtime = explode(' ', $mtime);
    $secs = $mtime[1] + $mtime[0];
    return $secs;
}

function execTime($start) {
    $end = startTime();
    $total = $end - $start;
    return '<Br>'.sprintf('Executed in %.6f seconds.', $total);
}

//Usage

$start = startTime();

//the code.....

echo execTime($start);

Place startTime() at beginning where timing is to start. Get the return value and set the start time variable. At end of script to time call execTime($start) passing the start time and this will calculate elapsed time of execution.

PHP Code Execution Timing Script

php

PHP