remaining time in php IE 1d 13m 3s

<?php
echo remainingTime('1767805200');

function remainingTime($startdate){  //TIME STAMP
    $rem = $startdate - time();
    $remainings="";
    $day = floor($rem / 86400);
    $hr  = floor(($rem % 86400) / 3600);
    $min = floor(($rem % 3600) / 60);
    $sec = ($rem % 60);
    if($day){ $remainings=$remainings."".$day."d";}
    if($hr){ $remainings=$remainings."".$hr."h ";}
    if($min) { $remainings=$remainings."".$min."m ";}
    if($sec) { $remainings=$remainings."".$sec."s ";}
    return $remainings;
}