Most theories of personality development posit that changes in life circumstances (e.g. due to major life events) can lead to changes in personality, but few studies have examined the exact time course of these changes. In this article, we argue that time needs to be considered explicitly in theories and empirical studies on personality development. We discuss six notions on the role of time in personality development. First, people can differ before the event. Second, change can be non–linear and discontinuous. Third, change can be reversible. Fourth, change can occur before the event. Fifth, control groups are needed to disentangle age–related and event–related changes. Sixth, we need to move beyond examining single major life events and study the effects of non–normative events, non–events, multiple events, and minor events on personality. We conclude by summarizing the methodological and theoretical implications of these notions. Copyright © 2014 European Association of Personality Psychology