The ways in which we experience and reason about time are fundamental aspects of human cognition. Both philosophers and cognitive scientists have struggled to explain the origins of our multifaceted, abstract concept of time. One means of exploring the nature of time in the adult mind is by asking how the ability to mentally represent and reason about time develops in children. Although some aspects of temporal cognition, like low-level duration perception, are present at birth, others, like using a clock, take up to a decade to learn. By tracking how different time-related cognitive phenomena emerge and change across development, we may gain a fuller picture of how the many facets of time interrelate, including the biological and cultural factors that underlie them. This symposium brings together researchers from around the world to discuss five different aspects of children’s temporal cognition, each of which change dramatically during the preschool years.