te tengo otra...
Código PHP:
$f1=strtotime("2007-01-29 16:27:31");
$f2=strtotime("2007-01-28 13:52:12");
$diff = $f1 - $f2;
echo "la diferencia es: ".date('d',$diff)." Dias, ".date('h',$diff)." Horas, ".date('i',$diff)." Minutos, ".date('s',$diff)." Segundos";