A more thorough explanation:

A sunset law, also called a sunset provision, is a law that automatically ends an agency, law, or government program if it doesn't get approval from lawmakers within a certain amount of time.

For example, let's say a state creates a program to help prisoners with drug addiction. The law that created the program might say that it will end in two years if lawmakers don't review and approve it. This is to make sure that the program is still needed and working well.

The sunset law was made in the 1970s in the United States to make government more efficient. It makes lawmakers look at the programs they've created and decide if they're still necessary.

Another example of a sunset law is the Patriot Act. This law was passed after the 9/11 attacks to help prevent terrorism. But it had a sunset provision that made it expire after a certain amount of time. This was to make sure that lawmakers would review it and decide if it was still needed.

The examples show how sunset laws work. They make sure that lawmakers review programs and laws to make sure they're still needed and working well. If they're not, the program or law will end.