Помогите новичку с функцией

<?php
function wtime($timediff){
   $oneMinute=60; $oneHour=60*60; $oneDay=60*60*24;
   $dayfield=floor($timediff/$oneDay);
   $hourfield=floor(($timediff-$dayfield*$oneDay)/$oneHour);
   $minutefield=floor(($timediff-$dayfield*$oneDay-$hourfield*$oneHour)/$oneMinute);
   $secondfield=floor(($timediff-$dayfield*$oneDay-$hourfield*$oneHour-$minutefield*$oneMinute));
   
if ($dayfield>0){
$d="$dayfield дней";
}else{
$d='';
}
  
if ($hourfield >0){
$h="$hourfield час.";
}else{
$h='';
}

if ($minutefield>0){
$m="$minutefield мин.";
}else{
$m='';
}


if ( $secondfield >0){
$s=" $secondfield сек.";

}else{
$s='';
}


$time="$d $h $m $s";
   return $time;
}

$r=300;
echo wtime($r);

 echo"</br>";
$m=56;
echo wtime($m);

 echo"</br>";
$t=3000;
echo wtime($t);

 echo"</br>";
$i=305560;
echo wtime($i);

 echo"</br>";
$w=3600;
echo wtime($w);

 echo"</br>";
$r2=200;
echo wtime($r2);
echo"</br>";
$o=86400;
echo wtime($o);

echo"</br>";


?>

function wtime($file_time){

        if($file_time >= 86400){
            $file_time = round((($file_time / 60) / 60) / 24).' д.';
        }elseif(
            $file_time >= 3600){
            $file_time = round(($file_time / 60) / 60, 1).' ч.';
        }elseif(
            $file_time >= 60){
            $file_time = round($file_time / 60).' мин.';
        }else{
            $file_time = round($file_time).' сек.';
        }
        return $file_time;
}