Three school districts examine cooperatively the implications of extending the academic calendar into the summer months and a tentative future curriculum. The study recommends: (1) a school year composed of five 9-week terms; (2) the introduction of travel- and work-study experiences into the credit structure of existing curricula; (3) the addition of a fifth (summer) term to permit additional student attendance options; and (4) increased interdistrict cooperation in the areas of planning, facilities utilization, transportation sharing, and student interdistrict attendance. (Floor plans on pages 151-153 and map on page 159 may reproduce poorly.) (Author/MLF)