Cal. Government Code § 911.4

(a) When a claim that is required by Section 911.2 to be presented not later than six months after the accrual of the cause of action is not presented within that time, a written application may be made to the public entity for leave to present that claim. (b) The application shall be presented to the public entity as provided in Article 2 (commencing with Section 915) within a reasonable time not to exceed one year after the accrual of the cause of action and shall state the reason for the delay in presenting the claim. The proposed claim shall be attached to the application. (c) In computing the one-year period under subdivision (b), the following shall apply: (1) The time during which the person who sustained the alleged injury, damage, or loss as a minor shall be counted, but the time during which he or she is mentally incapacitated and does not have a guardian or conservator of his or her person shall not be counted. (2) The time shall not be counted during which the person is detained or adjudged to be a dependent child of the juvenile court under the Arnold-Kennick Juvenile Court Law (Chapter 2 (commencing with Section 200) of Part 1 of Division 2 of the Welfare and Institutions Code), if both of the following conditions exist: (A) The person is in the custody and control of an agency of the public entity to which a claim is to be presented. (B) The public entity or its agency having custody and control of the minor is required by statute or other law to make a report of injury, abuse, or neglect to either the juvenile court or the minor’s attorney, and that entity or its agency fails to make this report within the time required by the statute or other enactment, with this time period to commence on the date on which the public entity or its agency becomes aware of the injury, neglect, or abuse. In circumstances where the public entity or its agency makes a late report, the claim period shall be tolled for the period of the delay caused by the failure to make a timely report. (3) The time shall not be counted during which a minor is adjudged to be a dependent child of the juvenile court under the Arnold-Kennick Juvenile Court Law (Chapter 2 (commencing with Section 200) of Part 1 of Division 2 of the Welfare and Institutions Code), if the minor is without a guardian ad litem or conservator for purposes of filing civil actions.