def _year_from_2digits(short_year, current_year):
        """
        Converts a relative 2-digit year to an absolute 4-digit year
        :param short_year: the relative year
        :param current_year: the current year
        :return: the absolute year
        """
        if short_year < 100:
            short_year += current_year - (current_year % 100)
            if abs(short_year - current_year) >= 50:
                if short_year < current_year:
                    return short_year + 100
                else:
                    return short_year - 100
        return short_year