Andover operates on a trimester system. The year begins in September and ends in June, with breaks in December and in the early spring. Students normally have three or four class meetings per day. Classes are held on Monday, Tuesday, Thursday and Friday, the full class days, and on Wednesday morning and selected Saturday mornings in the fall and spring terms. Classes do not meet on Sunday.

This flexible weekly schedule provides time for independent study, rehearsals and sports, for informal visits to the art and archaeology museums and for student-run extracurricular organizations such as the literary magazines, the school newspaper, the school radio station and the many student clubs. Social events during the week are limited by the demands of the academic program, but the weekend program on campus includes dances, concerts, movies, plays and informal activities.

Participation in athletics is required of all students, and athletic activities are scheduled four afternoons a week for approximately two hours each. On Wednesday and Saturday afternoons, varsity and junior varsity teams participate in interscholastic competitions.

Meals are served in Commons, the central dining hall, which is composed of four handsome, traditional dining rooms and four completely modern serving areas. The cost of meals is included in the fees of both boarding and day students.

Course work is intensive and involves about 20-25 hours of outside preparation each week. On nights before classes study hours begin at 8 p.m.; students who use their free periods during the day to study can usually finish their homework by the end of these study hours. During these hours, students are required to be signed in either to their dormitories or to an academic area on campus.

Required athletics or afternoon activities total approximately six hours each week. In addition, all students are required to participate in the school's work program, performing assigned tasks or supervising them for two hours each week. Despite the amount of time that must be spent on academic pursuits, most students become very involved in extracurricular activities and social events. By allowing students to make some choices about how they spend their time, Andover encourages independence and personal responsibility.