California Code, Health and Safety Code - HSC § 1596.807

The State Department of Social Services, shall allow an extended daycare program, whether or not exempt from licensure pursuant to subdivision (h) of Section 1596.792, to serve additional children at that school site, so long as they are currently enrolled in a school, including transitional kindergarten, as defined in Section 48000 of the Education Code, and the number of additional children, including dependent children living within the same household as a child attending that school, does not exceed 15 percent of the total enrollment in the extended daycare program. In no case shall the enrollment of the extended daycare program exceed the enrollment during the regular schoolday.