Almost all minors under the age of 18 are subject to California's child labor protections. All minors who have not graduated high school or been awarded a certificate of proficiency, must have a valid work permit.Children ages 12 and 13 can only work on days when there is no school. The law allows them to work up to eight hours a day and no more than 40 hours a week. Minors under 16 may work 8-40 during non-school day or week. 8-30-6 during schoolyear. Corey Franklin is a management labor and employment partner based in St. Louis, MO. Corey is admitted to practice law in Missouri and Illinois. These regulations set the minimum ages for employment and limit the number of hours that minors can work, especially during school hours.