Welcome to the Cosmic Calendar Website! Use our time conversion tool below to get an idea of time on different planets. Year 1, Day 1, midnight is the same for every planet. The number of years you see displayed are the number of years that have passed since then. Planets like Saturn and Neptune have years that last hundreds of Earth years. Other planets closer to the sun have much shorter years, but often long days. You can also explore the other pages on our website to learn more about the planets.