Research in the field of time-related academic behaviour (i.e., procrastination and timely engagement) has traditionally been focused on more stable factors, such as personality. Recent research suggests there may be a motivational component to these behaviours. The present study examines whether time-related academic behaviour is stable across time and context, and the degree to which change is predicted by contextual and motivational factors. The sample was comprised of 453 undergraduate college students at a large public university in the Midwestern US. We found that time-related academic behaviours were not stable, and changes in those behaviours were most closely linked to changes in self-efficacy, self-regulation and mastery-approach achievement goals.