The 1990-91 Schools and Staffing Survey (SASS), surveyed nationally representative samples of public and private school teachers and asked them about their work-related time commitments at the school site and away from the site. Items from this survey, together with comparable items from the 1987-88 SASS, provide a picture of how much time teachers spend in teaching and teaching-related activities. In 1990-91, teaching required just about 46 hours of work each week. About 11 of these hours each week were spent by teachers outside their schools in school-related activities, either interacting with students or working on their own. Such a workload indicates a need for more research on teachers' use of time and the implications of alternative time-use strategies for implementation of professional standards and educational reform activities. (MLF)