The socialization of children and adolescents is shaped by how they spend their time. This special issue maps the daily experience of white American 5th-9th graders, describing both the quantities of time they spend in different contexts and the affective states associated with these contexts. Each paper examines a separate segment of daily activity (e.g., schoolwork, talking, sports), employing data from a common study in which 401 participants provided "experience sampling" reports at random times during their daily lives when cued by a pager. The findings show substantial age and sex differences, indicating significant changes in the daily "life space" of girls and boys between preadolescence and early adolescence. Implication for socialization to healthy adult adjustment in love, work, and play are discussed in each paper.