Cal. Health and Safety Code § 1597.63

(a) At least one family daycare home licensee shall be present in the home and shall ensure that children in care are provided care and supervision during all hours of operation. (b) (1) Notwithstanding subdivision (a), when circumstances require a licensee to occasionally be temporarily absent from a family daycare home when children in care are present, the licensee shall arrange for a substitute adult to provide care and supervision of the children in care if the family daycare home operates during the temporary absence. (2) A temporary absence of the licensee shall not exceed 20 percent of the hours that the family daycare home is providing care in any given calendar month unless otherwise determined by the department. (3) The department may waive the requirements of this subdivision on an individual basis if the waiver is reasonable and necessary to carry out this act and not detrimental to the health and safety of any child in care. (c) Prior to a substitute adult’s initial presence in a family daycare home, a licensee shall ensure the substitute adult does all of the following, and complies with any additional requirements established by the department: (1) Obtains a criminal record clearance or exemption pursuant to Section 1596.871. (2) Completes the health and safety training described in Section 1596.866, as demonstrated by a current course completion card in pediatric first aid, pediatric cardiopulmonary resuscitation (CPR), and preventive health practices. (3) Is immunized against influenza, pertussis, and measles pursuant to Section 1597.622. (d) A family daycare home shall provide prior written notice to the parent or legal guardian of each child in care regarding any temporary absence of the licensee. If prior notice is impractical based on emergency circumstances, then written notice shall be provided no later than the next business day following the temporary absence. (e) A family daycare home shall maintain documentation of compliance with this section and with Sections 1596.866, 1596.871, and 1597.622 regarding a substitute adult. (f) Notwithstanding the rulemaking provisions of the Administrative Procedure Act (Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code), the department may implement and administer this section through letters or similar written instructions that shall have the same force and effect as regulations until regulations are adopted.