Retirement of a judge shall become effective:
(1) Where compulsory, when he reaches the age of seventy years, except as otherwise provided in R.S. 11:1352.
(2) Where voluntary, upon the date specified in the notice of retirement which he shall give to the governor and secretary of state.
(3) Where he is retired for incapacity, when the certificate of incapacity is filed with the secretary of state.