Amazingly, a single day on Venus is longer than its entire year. It takes Venus 243 Earth days to completely rotate on its axis, but just 225 days to orbit the sun. Stranger still, Venus is one of two planets that rotates in reverse, a phenomenon called retrograde motion. Most theories attribute the reverse rotation to an ancient planetary collision.
Bird's-eye view of the north side of the solar system, whereby the planets revolve counterclockwise around the sun. When the faster-traveling Earth bypasses a slower-moving outer planet, that planet appears to go westward relative to the background stars for a few to several months, centered on that planet's opposition (3). Image credit: Wikipedia
What is retrograde motion? | EarthSky 2/6/17 Retrograde motion of Jupiter or Mars or Saturn in our sky is an illusion, caused by Earth’s passing these slower-moving outer worlds. But there’s a real retrograde motion, too. Animation of Mars in retrograde