Object-Oriented Introduction to Java - Multimedia Introduction to Programming Using Java - page 53

paints a house, with a door, window, and roof.
E13. Write (and test) a class that maintains a time (hour and minute of the day).
There should be a way for a use to indicate that they want 12-hour time (e.g.
8:20PM or 8:10AM) or 24-hour time (e.g. 20:20 or 8:10), and method toString
should produce whatever is desired. The complete design of the class is up to
you, but remember, fields should be private.