PHP berechnet den Zeitunterschied

   function getTime($startdate,$enddate){        
   $startdate = strtotime('2017-01-01 12:12:12');        
   $enddate = strtotime('2017-01-02 13:13:13');        
   $date=floor(($enddate-$startdate)/86400);
//        echo "相差天数：".$date."天<br/><br/>";        
   $hour=floor(($enddate-$startdate)%86400/3600);
//        echo "相差小时数：".$hour."小时<br/><br/>";        
   $minute=floor(($enddate-$startdate)%86400%3600/60);
//        echo "相差分钟数：".$minute."分钟<br/><br/>";        
   $second=floor(($enddate-$startdate)%86400%3600%60);
//        echo "相差秒数：".$second."秒";        
   return $date*24+$hour.'小时'.$minute.'分'.$second;    
   }