def has_active_billing_periods(self) -> bool:
        """
        Returns True if current date is within the billing term.
        If either start or end date is None, returns False.
        """
        if not self.is_billing_terms_dates_set():
            return False

        if TYPE_CHECKING:
            assert self.current_billing_term_starts_at is not None
            assert self.current_billing_term_ends_at is not None

        starts_at = self.current_billing_term_starts_at
        ends_at = self.current_billing_term_ends_at
        now = timezone.now()

        return starts_at <= now <= ends_at

        Returns True if current date is within the billing term.
        If either start or end date is None, returns False.
        
api/organisations/models.py