No person, either for himself or for any firm, association, or corporation, shall, during the hours the public schools are in session, accept service from, engage, or employ any child under eighteen (18) years of age, unless such employer shall have on file an employment certificate, or farm or domestic service permit, issued according to law.
If the child leaves such employment, or is absent from such employment five (5) days, the employer shall immediately, in writing, notify accordingly the school official who issued the certificate.
24 P.S. § 13-1391