I can’t believe I almost missed this.
Naval History and Heritage Command : About
In 1972 Chief of Naval Operations (CNO) Admiral Elmo R. Zumwalt authorized recognition of 13 October as the Navy?s birthday. In contrast to Navy Day, the Navy Birthday is intended as an internal activity for members of the active forces and reserves, as well as retirees, and dependents. Since 1972 each CNO has encouraged a Navy-wide celebration of this occasion "to enhance a greater appreciation of our Navy heritage, and to provide a positive influence toward pride and professionalism in the naval service."
Fair winds and following seas.