PHPで年齢を計算する簡単な方法

/**
* $date是时间戳
* $type为1的时候是虚岁,2的时候是周岁
*/
function getAgeByBirth($date,$type = 1){
   $nowYear = date("Y",time());
   $nowMonth = date("m",time());
   $nowDay = date("d",time());
   $birthYear = date("Y",$date);
   $birthMonth = date("m",$date);
   $birthDay = date("d",$date);
   if($type == 1){
    $age = $nowYear - ($birthYear - 1);
   }else{$type == 2}{
    if($nowMonth<$birthMonth){
     $age = $nowYear - $birthYear - 1;
    }elseif($nowMonth==$birthMonth){
     if($nowDay<$birthDay){
      $age = $nowYear - $birthYear - 1;
     }else{
      $age = $nowYear - $birthYear;
     }
    }else{
     $age = $nowYear - $birthYear;
    }
   }
   return $age;
}