The term “apprentice” as used in this chapter, means a person at least 16 years of age who has entered into a written agreement, in this chapter called an “apprentice agreement,” with an employer or program sponsor. The term of apprenticeship for each apprenticeable occupation shall be approved by the chief, and in no case shall provide for less than 2,000 hours of reasonably continuous employment for such person and for his or her participation in an approved program of training through employment and through education in related and supplemental subjects.