Wrong type handling in funktion resi_make_calendar

On line 171 parameter 6 on function call should be of type long instead string.

This line
$starttag_stamp = mktime(0, 0, 0, $pieces[1] , $pieces[2], $pieces[0]);
should be replaced by
$starttag_stamp = mktime(0, 0, 0, $pieces[1], $pieces[2], intval($pieces[0]));