Time is an underdeveloped aspect of textbook reading analytics. We used the Living Textbook, a concept-based digital textbook, to collect tracking data during an introductory MSc course. In this paper, we compare first-time concept visits versus subsequent concept visits, the time when these concept visits occur and the duration of the concept visits. With the collected information, we want to optimize the length and order of the learning pathways. Although many concept visits are generated close to the exam at the end of the course, these are often re-visits, indicating a review before the exam rather than procrastination.