“specified date”, in relation to any company, means –

(a)     in respect of the year of assessment ending the thirtieth day of June, 1962, that date or, if such company’s return is under the proviso to subsection (13) of section 66 accepted in respect of a period ending upon some other date, such other date; or

(b)     in respect of any other year of assessment, the last day of such other year of assessment;