Background: Feelings of satisfaction fluctuate across time and situations, and focusing on within-person experiences opens up the door to a better understanding of the daily lives of university students. Aims: Our overarching goal was to situate academic satisfaction not only as a relatively enduring characteristic but also as a transient state that fluctuates across days in the lives of student. In the present study, we explored how optimism and pessimism related to inter-individual differences in academic satisfaction. We also investigated the association between coping and academic satisfaction at both the between- and within-person levels. Sample: A sample of 235 undergraduate students (M[subscript age] = 19.14) participated in this study. Method: Students completed baseline measures of optimism and pessimism. They were then asked to complete daily-diary measures of academic coping strategies and academic satisfaction during six consecutive days. Results: At the "between-person" level, results from multilevel mediation analyses demonstrated that optimism was associated with greater academic satisfaction and that task-oriented coping was a significant mediator of this association. At the "within-person" level, our analyses revealed that the daily satisfaction of students varies according to the coping strategies used on those specific days. Almost half of the variance in academic satisfaction can be attributable to daily fluctuations. Conclusions: This source of within-person variance is non-negligible and supports the need to also conceive academic satisfaction as "a question of when." These findings illustrate the importance of considering the role of personality and daily coping to better conceptualize and understand academic satisfaction of university students.