(a) The normal retirement date of a member shall be the first day of the month coinciding with or next following the date he reaches the age of 65, except that the normal retirement date of a member who is age 64 or over on January 1, 1970, shall be January 1, 1971. A member shall retire on his normal retirement date except as otherwise provided in subsections (b) through (e) of this Code section.

(b) At the request of his local unit of administration, a member may remain actively employed beyond his normal retirement date on a year-to-year basis as shall be mutually agreed upon by the member and his local unit of administration. In such cases, the member shall retire on the first day of the month coinciding with or next following the end of the last agreed upon period of employment, which date shall be the delayed retirement date of the member.

(c) Any person who was a public school employee for a period of ten or more years at any time after July 1, 1945, and who on April 14, 1971, had attained age 60 or over shall be eligible for membership and may retire. The effective date of such individual's retirement shall be the first day of the first month which occurs at least 30 days after receipt of his application for retirement by the board of trustees. Such effective date shall be the early retirement date of the member.

(d) Except as provided in subsection (c) of this Code section, the early retirement date of a member shall be the first day of the month coinciding with or next following the date he attains the age of 60. A member may elect to retire at his early retirement date and receive the retirement benefit provided by subsection (d) of Code Section 47-4-101.

(e) The right to a retirement benefit under this chapter shall vest in a member who has ten or more years of creditable service if he has not withdrawn his contributions. Upon attaining his normal retirement age or his early retirement age, he shall begin receiving the appropriate retirement benefit provided by Code Section 47-4-101.