Ring-sized watch

Looks great!

Just to add that digitalWrite can take an array of pins, so certain things can be really simplified/sped up. For example:

for (var a in anodes) {
    digitalWrite(anodes[a], 0);
  }
// is the same as
digitalWrite(anodes, 0);

and similarly if you have a bit pattern that you want to output to all anodes at once you can do digitalWrite(anodes, pattern);.