Even the standard PHP string parser does 0.017ms on my 3 year old netbook.

    <?php

    $st = microtime(true);
    $cnt = 10000;

    for ($i=0; $i<$cnt; $i++)
    	strtotime('2014-01-09T21:48:00.921000');

    echo 1000 * (microtime(true) - $st) / $cnt;