For the purposes of this Act, where the period of service of a member or former member comprises a number of periods that are not continuous with one another and 2 or more of which are periods other than a complete year or an exact number of complete years, the number of complete years in that period of service shall be taken to be the sum of:
(a) the numbers of complete years in the periods comprised in that period of service; and
(b) the number ascertained by dividing the total of the number of days remaining in those periods by 365 and disregarding any fraction in the number so ascertained.