Practices of periodization and the reliance on linear notions of time have been an object of sustained critique in recent times. Not only have they been said to impose uniformity on the complex and multi-stranded course of art, they have also been accused of enabling an ideological agenda that privileges the art and culture of Western Europe and North America. In their place it has been suggested that art historians embrace alternative ideas of time, including notions of time as entangled, heterochronic and anachronic. This chapter examines the basis of such criticisms. It argues that while they highlight important issues, they also misrepresent art historical practice, including the heuristic function of the idea of periods. The chapter also argues that such alternative metaphors conflate historical narratives with temporal horizons. Without shared temporal horizons, it is impossible to make meaningful judgements of difference when comparing the art historical trajectories of different cultures. Consequently, the chapter suggests, the project of entangled, heterochronic and anachronic art history may end up being counterproductive.