<?
$nowtime=date("Y-m-d", time());

  $ntime=explode("-",$nowtime); 

$birthage=19730913;
$year=substr($birthage,0,-4);
$month=substr($birthage,4,-2);
$day=substr($birthage,6);

$manage = $ntime[0]-$year; 
  if($ntime[1]<$year){ $manage--;  echo" 만 $manage 세"; }
  else{ echo" 만 $manage 세"; }
?>