I recently purchased a lunar clock intended as a Christmas present for a young family friend who has become interested in astronomy. The clock face shows twelve images of the Moon in all its main phases, with the Full Moon depicted at the "twelve o'clock" position. Now I purchased this clock especially early to allow time to check on its accuracy. After waiting for a full lunar orbit to occur, I have since discovered that the clock time when measured relative to its lunar images (that's to...