The calendar systems used at 3,387 colleges and universities in 1982 were identified. Comparisons to the systems used in 1978 and 1981 also were made. It was found that the predominant calendar type in use has been and continues to be the semester. From 1978 to 1981, there was a 2 percent increase in the use of the semester system nationwide, with increases in areas of the Mideast, Southeast, the Great Lakes, and the Plains. The types of calendars used in 1982 and the percentage of colleges using each type were as follows: semester (57 percent), quarter system (23 percent), trimester (4 percent), 4-1-4 system (8 percent), and other (8 percent). Institutions with a semester system tended to have liberal arts, teacher preparation, or professional programs, as well as stricter admission requirements. Colleges and universities that were single sex, with larger enrollments, or in large population areas, also tended to have a semester system. Private colleges were more likely to use the trimester, 4-1-4, or other systems. Appendices include a position paper on the early semester system, a list of urban universities, and information on a multiple discriminant analysis of the academic calendar system by selected institutional characteristics. (SW)