How often do planets change Zodiac signs?

Planets don’t just lounge around the galaxy sunning themselves on the galactic beach. They move all the time. They are in perpetual motion, like my brain. (I am a Gemini after all). Each planet has its own path around the Sun and its own timeframe for making the loop. The closer the planet is to the Sun, the faster the trip. As the planets move, they pass by different sections of the ecliptic plane - that thin ribbon-like band encircling the Sun. Behind the ecliptic plane are the constellations - also known as zodiac signs. So as the planets race across the heavens they are always in a zodiac sign.