Procrastination is an educational concern for classroom instructors because of its negative psychological and academic impacts on students. However, the traditional view of procrastination as a unidimensional construct is insufficient in two regards. First, the construct needs to be viewed more broadly as time-related academic behavior, encompassing both procrastination and timely engagement. Secondly, the underlying motivation of these behaviors needs to be considered. Therefore, we developed and validated a 2 x 2 model of time-related academic behavior. The results of a confirmatory factor analysis supported a four-factor structure, and correlation with a unidimensional measure of procrastination also supported this model. Furthermore, the 2 x 2 model demonstrated significantly better fit to the data than potentially competing models. Structural equation modeling with achievement goals revealed that the 2 x 2 model unveiled relationships previously obscured in the traditional model, including that procrastination appeared to be used as a performance-enhancing strategy, while timely engagement was used to enhance mastery. The theoretical and practical implications of these new relationships are discussed. (Contains 3 tables and 3 figures.)