This clock by Matt Zimmerman spells out the exact time every five minutes. The two minutes before and the two minutes after are the exact time plus “ish”. You’ll love it!
Update: Matt is working on a new mahogany version, with inlaid epoxy letters.
The Code
This program requires the FastSPI library. The specific version we used is posted here.
Wiring Diagram
Here are some pictures of how the resistors and switches are connected.