More ideas from Rachelle
Could do something like this if I modified the arms of a clock to be loosely telescoping so they only display 3-9.

Part-time, photo by Eke Miedaner. From the comments: "Shy clock?" "The clock is two-faced, so you have to take a look on both sides to know the time." (This is an official school-clock in KV Baden-Zurzach).