CBPCalc::addWorkDay

private function addWorkDay($date, $days)
{
	$delta = 86400;
	if ($days < 0)
		$delta *= -1;

	$days = abs($days);
	$iterations = 0;

	while ($days > 0 && $iterations < 1000)
	{
		++$iterations;
		$date += $delta;

		if ($this->isHoliday($date))
			continue;
		--$days;
	}

	return $date;
}