A small MODX snippet to time other snippets

now.php

<?php
/*
 * A small MODX snippet to time other snippets - (c) 2012 ackwa.fr 
 *
 * @see     : https://gist.github.com/gists/3169775
 * @name    : now.php
 * @author  : g.noel@ackwa.fr
 * @usage   : [[!now]]            -> First call
 *            [[!now?seed=`1`]]   -> subsequent calls
 *
 * @history : 24/06/12 - 1.0.0 - Initial revision
 */
$fNow   = microtime(true);
$sSeed  = ((isset($seed) && $seed ) ? $seed : 0);
$fPrev  = &$_SESSION['acknow'];
$fDelay = ($sSeed ? ($fNow - $fPrev) : '');
$fPrev  = $fNow;

return $fDelay;