Legacy code is anything older than...

How do you define legacy code?

Code that was written by someone else?

Code that doesn't have tests?

Any code that has been released to production?

Code that's more than a day old?

In a talk I recently watched, the speaker suggested that any code written more than thirty minutes ago is legacy code.

Once you've written some code and left it for half an hour, you need to re-read it to remember and re-learn what the code does and decide how you want to implement your next requirement.

This is the same approach for code that was written longer ago or written by someone else.

What do you think?