The scientific definition of a year is the amount of time it takes for a planet to make one revolution around the Sun. Earth’s neighbouring planet, Venus, takes 225 Earth days to revolve around the sun. The definition of a day is how long it takes for a planet to do one complete rotation on its own axis. It takes Venus 243 Earth days to do this. In other words, a day on Venus is longer than a year on Venus. The rotation of Venus on its axis is retrograde. It rotates in the opposite direction of Earth and the other planets in the Solar System (Uranus spins on its side).