(1)Every teacher or member of the non-teaching staff employed in any aided, private educational institution, not belonging to last grade service, shall retire from service on the afternoon of the last day of the month in which he attains the age of fifty eight years:Provided that a teacher or a member of the nonteaching staff aforesaid, who has already attained the age of fifty-eight years and continuing in service on the date of commencement of the Andhra Pradesh Education (Amendment) Act, 1993, shall retire on the afternoon of the last day of the month of the commencement of the said Act.