Before outlining a proposal for a flexible trimester calendar to replace the traditional semester system at San Bernardino Community College, other alternatives such as the early semester, 4-1-4, and quarter systems are reviewed. The proposed trimester system, developed in accordance with the California Flexible Calendar and School Finance in Community Colleges Pilot Program to meet the needs of increasing numbers of nontraditional students, would involve 35 weeks of instruction (the state required minimum of 175 days), divided into two, fourteen-week terms and one seven-week term. The seven-week term offers various options: a regular, unrevised summer session, a full, twelve-week term for courses requiring more time, and a fourteen-week term all of which could run concommitantly with the seven-week session. Term I would begin the day after Labor Day and end mid-December; Term II would begin following a three-week break and run through to mid-April, after which classes would break for two weeks prior to beginning Term III. The problems the new system would present in scheduling the traditional 48 hours of classroom instruction required in three-unit courses are resolved by longer class periods and the benefits that would accrue to students, faculty, and staff are reviewed. Appendices explore scheduling for various programs in the trimester calendar. (TR)