Cal. Education Code § 37670

(a) Except as provided in Article 2 (commencing with Section 37680), a school district may operate a program of multitrack year-round scheduling at one or more schools within the district. A program of multitrack year-round scheduling may operate at a schoolsite for as few as 163 days in each fiscal year if the governing board of the school district adopts a resolution at a regularly scheduled board meeting certifying that both of the following criteria are met at the schoolsite: (1) The number of annual instructional minutes is not less than that of schools of the same grade levels utilizing the traditional school calendar. (2) It is not possible for the school to maintain a multitrack schedule containing the same number of instructional days as are provided in schools of the district utilizing the traditional school calendar given the facilities, program, class sizes, and projected number of pupils enrolled at the schoolsite. (b) A certificated employee working under a program described in this section, except one serving under an administrative or supervisorial credential who is assigned full time to a school in a position requiring qualifications for certification, shall work the same number of days and shall increase the number of minutes worked daily on a uniform basis. (c) A program conducted pursuant to this section is eligible for apportionment from the State School Fund.