function getCorrespondingMetadates($termin_id, $begin = '', $end = '', $seminar_id = '')
{
$termin = new SingleDate($termin_id);
if (!$termin->getMetaDateID()) {
return false;
}
if (!$seminar_id) {
$seminar_id = $termin->getRangeID();
}
$sem = new Seminar($seminar_id);
$turnus = $sem->getFormattedTurnusDates();
return $turnus[$termin->getMetaDateID()];
}