Time across the term: Weekly dynamics and anticipated time use as predictors of motivation in introductory chemistry

College students regularly shift time among coursework, employment, and leisure as demands change across a semester. Drawing on situated expectancy-value theory and a multiple-goals framework, we used intensive longitudinal data from an introductory chemistry course (N = 440) to examine how weekly deviations in time use, semester averages, and baseline expectations predicted motivation (competence, interest, importance value, and four costs). Time use was more consistently linked to competence and costs than to interest or importance. Within persons, weeks with more chemistry study than usual predicted higher competence and most costs; more time on other courses or employment predicted higher outside effort and emotional cost, whereas more leisure predicted higher competence and importance. Between persons, consistently higher chemistry time predicted higher interest and higher costs, while greater leisure predicted lower loss of valued alternatives cost. Anticipating heavier workloads predicted higher interest and lower costs.