Calculate MySQL Execution Time/Duration; Calculate PHP Script Execution Time/Duration

<?php
$stats = array();
function start(){
    global $stats;
    $stats['time_start'] = microtime(true);
}

function stop() {
    global $stats;
    $stats['time_end'] = microtime(true);
    $stats['time_total'] = $stats['time_end'] - $stats['time_start'];
    echo 'completed in ' . $stats['time_total'] . ' seconds' . "\n";
    exit;
}

<?php // example usage
start();

for ($i = 0; $i <= 1000; $i++) {
    // Do something
}

stop();

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