def can_perform_swap(self):
        index = self.swap_type_list.selected_index
        if index == SwapType.DayMonth:
            return self._can_swap_date_fields(DAY, MONTH)
        elif index == SwapType.MonthYear:
            return self._can_swap_date_fields(MONTH, YEAR)
        elif index == SwapType.DayYear:
            return self._can_swap_date_fields(DAY, YEAR)
        else:
            return True