1. If a school board establishes part-time schools or classes for children under seventeen years of age, lawfully engaged in any regular employment, every parent, guardian or other person having charge, control or custody of such a child shall cause the child to attend the school not less than four hours a week between the hours of eight o’clock in the morning and five o’clock in the evening during the school year of the part-time classes.

2. All children who are under eighteen years of age, who have not completed the elementary school course in the public schools of Missouri, or its equivalent, and who are not attending regularly any day school shall be required to attend regularly the part-time classes not less than four hours a week between the hours of eight o’clock in the morning and five o’clock in the afternoon during the entire year of the part-time classes.