header('Content-type: text/html; charset=windows-1254');
header("Expires: Mon, 26 Jul 2018 05:00:00 GMT\n");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Content-type: application/zip;\n"); //or yours?
header("Content-Transfer-Encoding: binary");
$filename="download/$memberid/$zaman.zip";
$len = filesize($filename);
header("Content-Length: $len;\n");
$outname=$zaman.".zip";
header("Content-Disposition: attachment; filename=\"$outname\";\n\n");