DealExist::calculateBeginDate

protected function calculateBeginDate()
{
	$stringDate = '';
	if ((int)$this->getCalculateParameter('BEGINDATE_TYPE') === Recurring\Entity\Deal::CALCULATED_FIELD_VALUE)
	{
		$beginDate = Recurring\Entity\Deal::getNextDate([
			'MODE' => Recurring\Manager::MULTIPLY_EXECUTION,
			'MULTIPLE_TYPE' => Recurring\Calculator::SALE_TYPE_CUSTOM_OFFSET,
			'MULTIPLE_CUSTOM_TYPE' => (int)$this->getCalculateParameter('OFFSET_BEGINDATE_TYPE'),
			'MULTIPLE_CUSTOM_INTERVAL_VALUE' => (int)$this->getCalculateParameter('OFFSET_BEGINDATE_VALUE'),
		]);
		if ($beginDate instanceof Date)
		{
			$stringDate = $beginDate->toString();
		}
	}

	return $stringDate;
}