protected function getDateTime($propName) {
$prop = $this->getProperty($propName);
if (is_null($prop)) {
return null;
}
$dt = Vpdi::decodeDateTime($prop->value());
if (($tzid = $prop->getParam('TZID')) !== false) {
$dt->setTimezone(Vpdi::decodeTimezone($tzid));
}
return $dt;
}
