Proactivity and morningness have been variables of considerable study. Although many studies have examined the impact of either proactivity or morningness on performance, none have examined the impact of both concurrently. This study examines the relationship between proactivity and morningness empirically, as well as their impact on task performance. Using a pre-/post-test design, 189 students received training in proactive thinking. The training was conducted at two different times of day. The results indicate that proactivity and morningness both accounted for a significant portion of the variance in task performance. Also, the training was more effective when conducted at a time consistent with participants' time-of-day preferences.