protected static function createDaysList($days)
{
$_days = array();
foreach ($days as $day) {
$day = ltrim($day, "+");
$day = trim($day);
$ordwk = 0;
$weekday = false;
if (strlen($day) === 2) {
$weekday = $day;
} else {
list($ordwk, $weekday) = sscanf($day, "%d%s");
}
$_days[] = $ordwk . strtolower($weekday);
}
return $_days;
}