Before each Apollo voyage, the press and other interested parties were given circular cards like this one, which indicated each activity that was planned at any given "Mission Elapsed Time" (MET), defined as the time since launch.
This device shows the schedule for the Apollo 13 mission in April 1970. That plan was not followed, after an emergency on the way to the Moon.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.