Planets weren't "made" in a single year. They formed over millions of years, billions of years ago!

Here's a simplified timeline:

* The Big Bang: About 13.8 billion years ago, the universe began.

* Early Solar System: Around 4.5 billion years ago, a cloud of gas and dust started to collapse, forming our sun.

* Planet Formation: Over the next few million years, the leftover material from the sun's formation clumped together, eventually forming the planets.

So, while we don't have an exact year, we know that planets formed over a very long period of time, much longer than any human lifetime!