California Code, Military and Veterans Code - MVC § 368

(a) Each company, troop, squadron, battery, detachment, and unit shall assemble for drill and instruction, including indoor target practice, not less than forty-eight times each year unless excused by the Governor or other competent authority, and shall in addition thereto participate in encampments, maneuvers, or other exercises, including outdoor target practice, for at least fifteen consecutive days in each year unless excused by competent authority.

(b) In addition to the drills and periods of duty specified in subdivision (a), the commanding officer of any unit may require the officers and enlisted persons of their command to meet for parade, drill, and instruction at the times and places as they may appoint.