Subdivisions (a) and (d) of Section 5220 apply to subject corporations governed by the nonprofit public benefit corporation law and subdivisions (a) and (d) of Section 7220 apply to subject corporations governed by the nonprofit mutual benefit corporation law, provided that:
(a) If a director on January 1, 1980, is serving a term in excess of three years in duration, the director may continue to serve until December 31, 1982, or until the expiration of the term whichever is earlier.
(b) If, on January 1, 1980, more than one-third of the directors of a corporation hold office by virtue of designation or selection, they may continue to do so until December 31, 1982.