Cal. Gov. Code § 930.4

A claims procedure established by agreement made pursuant to Section 930 or Section 930.2 exclusively governs the claims to which it relates, except that if the procedure so prescribed requires a claim to be presented within a period of less than one year after the accrual of the cause of action and such claim is not presented within the required time, an application may be made to the public entity for leave to present such claim. Subdivision (b) of Section 911.4, Sections 911.6 to 912.2, inclusive, and Section 946.6 are applicable to all such claims, and the time specified in the agreement shall be deemed the “time specified in Section 911.2” within the meaning of Sections 911.6 and 946.6.