you’d hit: 5, 10, 3, 8, 1, 6, 11, 4, 9, 2, 7, 12. notice that it took twelve steps to get back to 12 o’clock, and we hit each hour exactly once!
of course, a seven-hour step would have done the same thing in reverse from 12 o’clock: 7, 2, 9, 4, 11, 6, 1, 8, 3, 10, 5, 12. this is because going seven hours forward is equivalent to going five hours backward, so the sequence is simply reversed.
except for the five-hour steps, none of the other step sizes up to six hours could possibly hit all the hours in this way (except for the obvious case of one-hour 