Minors aged 15 days to 18 years employed in the entertainment industry must have a permit to work, and employers must have a permit to employ. 16-17 age bracket- They can work for 4 hours in a day and 48 hours in a week during school days.The general rule is that the legal working age in California is 14-years-old, but anybody under the age of 18 must have a work permit. For most employers, a minor must be at least 14 years of age to work. Work Permits In California, most minors under the age of 18 must have a permit to work. In general, the legal working age in California is 14 years old. They can work up to 8 hours per day, and up to 40 hours per week. California's minimum legal age to work is generally 14 years old. If school is in session, children between the ages of 16 and 17 can work no more than four (4) hours on a school day. Minors who are 14 or 15 may only work 3 hours a day on school days.