The standard WAIT command makes time pass at the same rate that it would anyway - one minute per turn. In a game where events happen at specific times of day, though, we might want to give the player more control. Nine AM Appointment shows how to give the player a WAIT 10 MINUTES command, while Delayed Gratification lets him WAIT UNTIL a specific time of day.
Ordinarily, Inform also refuses to allow the player to SLEEP and WAKE UP: the commands exist, but have no effect. Change of Basis lets the player put himself into a sleep state in which he cannot do anything. A somewhat more interesting expansion on this idea would be to let the player sleep and have dreams; there are no examples specifically of dream states, but we might consult the examples on scenes about how to disrupt one environment and move the player to another, entirely new one.
See Scene Changes for ways to move the player to a new environment such as a dream state