“effective date”, in relation to any year of assessment of a provisional taxpayer, means –

 

(a)     where the provisional taxpayer is a company which has a year of assessment which ends on the last day of February or is a person (other than a company) who has not been granted permission by the Commissioner under the provisions of section 66(13A) to render accounts for a period ending on a date other than the last day of February, the date falling seven months after the last day of such year; or

 

(b)     in any other case, the date falling six months after the last day of such year as applicable for the purposes of the provisions of paragraph 21 or 23 of the Fourth Schedule;