Acculturation unfolds over time, but research on acculturation often does not account for developmental processes. Recent studies introduced several novel temporal concepts of acculturation processes to understand more fully how immigrant youth adapt to new cultural contexts. In this review, we describe these new temporal concepts of acculturation: Acculturative timing refers to youth's age at time of migration (chronological timing), the actual start of acculturative changes (which may occur before or after physical migration, also called transition timing), and the deviation in acculturative change from peers and relevant others from the same cohort and context (relative timing). Acculturation tempo is the duration of acculturation processes from start to a defined end. Acculturation pace is the speed at which acculturation occurs. Acculturation synchrony describes whether adaptation unfolds at the same or different times across different spheres of life. We also present empirical evidence for the predictive utility of the new temporal concepts and provide methodological guidelines on how to measure and assess these concepts. © 2022 The Authors. Child Development Perspectives published by Wiley Periodicals LLC on behalf of Society for Research in Child Development.