When timing information is expressed in the UI is as important as how to express it. Whether information is shown prospectively, in real time or retrospectively can significantly influence user's perception, behavior, and experience. This chapter provided some guidance for expressing time. In expressing time units, use time anchors to express ranges, limits, and remaining time to prevent users from thinking that estimations are exact. Some time expression grammatical rules and etiquette are also spelled out, such as singularizing singular units.