The first academic year involves a variety of challenges students must overcome to maintain their commitment to enter the teaching profession. Students can build on their initial experience in the second semester, while everything is new in the first semester. This longitudinal study investigates the interplay of academic self-efficacy and time management, which are seen as crucial in the first year, and their effects on pre-service teachers' commitment to their studies in the first year. By considering three measurement points in a random intercept-cross lagged panel model (RI-CLPM) to data from 579 students, we distinguish for the first time between-person and within-person effects and compare the students' experiences in the first and second semester. As expected, students with higher self-efficacy were more committed to their studies and reported better time management. We found considerable differences in the relationships between the first and second semesters at the within-person level, revealing that students' prior time management was not significantly connected with subsequent commitment in the first semester, but in the second semester. Surprisingly, students' self-efficacy showed a small negative relationship with commitment in both semesters. Theoretical and practical implications for students, lecturers, and higher education institutions are discussed.