Venus has the longest day of all the planets in our solar system. A day is the time a planet takes to spin once on its axis. While Earth takes 24 hours to complete one rotation (which we call a day), Venus takes about 243 Earth days to complete just one spin.

What’s even more interesting is that Venus spins in the opposite direction compared to most other planets. This means if you could stand on Venus, the Sun would rise in the west and set in the east – the opposite of what happens on Earth.

Now let’s look at the other planets:
- Mercury takes around 59 Earth days to complete one rotation – long, but still shorter than Venus.
- Earth has a 24-hour day.
- Jupiter spins very fast – it has the shortest day of all, taking only about 10 hours for a full rotation.

Because Venus spins so slowly, a single day on Venus lasts longer than its entire year (which is only about 225 Earth days). That’s why Venus is the planet with the longest day.

Understanding the rotation of planets helps us learn how time and climate work on different planets. It also helps scientists plan space missions and understand how the solar system formed.