Researchers from Teachers College and the University of Maryland sought to find out "what actually happens to children during an entire school day" so they asked elementary teachers to complete a time diary. From this, they computed how much time was spent on academic subjects, enrichment activities (for example, art, music, and health instruction), maintenance activities (like packing up or traveling between classrooms), and recess, with results broken down by students' race, gender, grade, special needs, family characteristics, and classroom characteristics. They found that white students were significantly more likely to have longer school days, that minority students spent more time on core subjects at the expense of recess and enrichment activities, that students in larger classes spent more time on academics, and that the type of school (private or public) explained a large percentage of the variance in the uses of students' time. "What Happens During the School Day?: Time Diaries from a National Sample of Elementary School Teacher," by Jodie Roth, Jeanne Brooks-Gunn, Miriam Linver and Sandra Hofferth, Teachers College Record, 2002 (free registration required).