Mercury is the planet with the shortest period of revolution of approximately 88 Earth days. However, Mercury’s period of rotation is about 59 Earth days. A planet’s period of revolution is the time it takes for one complete spin around the sun. This is different from a planet’s period of rotation, which is the spinning of a planet on its own axis. More information on this question: 1. Mercury: One year on planet Mercury takes just 87.97 earth days.