This work explores and ponders the ways in which temporal matters affect how individuals, groups, and larger collectives behave. It examines how people conceptualize time and live within prescribed and personal timeframes and how time is measured and enters into social psychological phenomena at multiple levels, in different functional roles, and as different types of processes. Chapters cover how temporal factors play a fundamental role in many key methodological areas of psychology, including causality, internal and external validity, comparisons of empirical information gained by different research strategies, and theories of measurement and error.