Anticipatory timing plays a critical role in many aspects of human and non-human animal behavior.  Timing has been consistently observed in the range of milliseconds to hours, and demonstrates a powerful influence on the organization of behavior.  Anticipatory timing is acquired early in associative learning and appears to guide association formation in important ways.  Importantly, timing participates in regulating goal-directed behaviors in many schedules of reinforcements, and plays a critical role in value-based decision making under concurrent schedules.  In addition to playing a key role in fundamental learning processes, timing often dominates when temporal cues are available concurrently with other stimulus dimensions.  Such control by the passage of time has even been observed when other cues provide more accurate information and can lead to sub-optimal behaviors.  The dominance of temporal cues in governing anticipatory behavior suggests that time may be inherently more salient than many other stimulus dimensions.  Discussions of the interface of the timing system with other cognitive processes are provided to demonstrate the powerful and primitive nature of time as a stimulus dimension.