CCalendarEvent::convertExDatesToInternalFormat

static function convertExDatesToInternalFormat(string $exDateString): string
{
	if (!empty($exDateString))
	{
		$exDates = explode(';', $exDateString);
		$result = [];
		foreach ($exDates as $exDate)
		{
			$result[] = self::convertDateToRecurrenceFormat($exDate);
		}
		$exDateString = implode(';', $result);
	}

	return $exDateString;
}