public function validateDateformats($file, $key, $validate_language)
	{
		if (empty($validate_language))
		{
			$this->output->addMessage(Output::FATAL, 'Array must not be empty', $file, $key);
			return;
		}

		foreach ($validate_language as $dateformat => $example_time)
		{
			$this->validateString($file, $key . '.' . $dateformat, '', $dateformat);
			$this->validateString($file, $key . '.' . $dateformat, '', $example_time);
		}
	}