CBPCalc::functionIsWorkDay

private function functionIsWorkDay($args)
{
	if (!CModule::IncludeModule('calendar'))
		return null;

	if (!is_array($args))
		$args = [$args];

	$ar = $this->ArrgsToArray($args);
	$date = array_shift($ar);
	$user = array_shift($ar);

	if ($user)
	{
		$date = $this->FunctionToUserDate([$user, $date]);
	}

	if (($date = $this->makeTimestamp($date, true)) === false)
		return null;

	return !$this->isHoliday($date);
}