Indeed, interaction design is design of *perceived* time. "Perceived"
qualifier is superfluous if you happen to be an experientialist (good book
on experientialism and on prototype theory of classification is "Women,
Fire, and Dangerous Things" by Lakoff). Incidentally we perceive gravity too
and can design to modify that perception.
Notice that attention is drawn to time intervals listed below when the time
intervals are violated. Hence design of attention is related but narrower
category than design of time.
To design time one needs to be aware of time properties.
