David Zweben published a project writeup showing how he built a Neopixel clock powered by an Arduino Pro Mini clone and a real time clock module:

After building my first Neopixel Clock, I decided I needed one for myself. There was no way I was going to solder 90 lengths of wire onto 180 tiny pads again, though, so I knew I needed to design a custom PCB. This necessitated a redesign of the entire clock, focused around making it as easy as possible to assemble.

Project info at zweben.org.

Check out the video after the break.