(a) The date a member's annuity, if any, becomes payable by each reciprocal system shall be determined by those provisions in force for each reciprocal system.
(b) In no case shall any annuity become payable nor be paid prior to the date the member retires from, and ceases to be, in the employ of an employer covered by a reciprocal system as defined in § 24-2-401(3).