def is_correct(self):
        """Check if the Daterange is correct : weekdays are valid

        :return: True if weekdays are valid, False otherwise
        :rtype: bool
        """
        valid = self.day in Daterange.weekdays
        if not valid:
            logger.error("Error: %s is not a valid day", self.day)
        # Check also if Daterange is correct.
        valid &= super(StandardDaterange, self).is_correct()
        return valid