phpタイムスタンプ回転時間分秒

function secsToStr($secs) {
    $r = '';
    if($secs>=86400){$days=floor($secs/86400);
    $secs=$secs%86400;
    $r=$days.' day';
    if($days<>1){$r.='s';}
    if($secs>0){$r.=', ';}}
    if($secs>=3600){$hours=floor($secs/3600);
    $secs=$secs%3600;
    $r.=$hours.' hour';
    if($hours<>1){$r.='s';}
    if($secs>0){$r.=', ';}}
    if($secs>=60){$minutes=floor($secs/60);
    $secs=$secs%60;
    $r.=$minutes.' minute';
    if($minutes<>1){$r.='s';}
    if($secs>0){$r.=', ';}}
    $r.=$secs.' second';
    if($secs<>1){$r.='s';
    }
    return $r;
}