Business and Professions Code section 18720

(a)

No boxing contest or match shall be more than 12 rounds of not more than three minutes each in length, except that championship contests may, if the written approval of the commission is first obtained, be 15 rounds of not more than three minutes each in length. The commission may limit the number of rounds in a contest within the maximum.

(b)

There shall be one minute rest between consecutive rounds.