the amount calculated with respect to that national tax, according to the period after the enforcement of this Act, in accordance with the calculation of the amount of interest tax payable under the provisions of the former tax laws (the provisions of the former tax laws concerning the simplified interest tax table are not to be applied, and the rate used in calculating that amount is to be two sen per day for every 100 yen of the amount of national tax that forms the basis of the calculation); and