This is the passage you're citing:

> Consider this: if you get access to an IQ test weeks in advance, you could slowly work through all the problems and memorize the solutions. The test would then score you as a genius. This reveals what IQ tests actually measure. It’s not whether you can solve problems, but how fast you solve them.

You retort that "if you can work on it for a week, then it's no longer an IQ test", but that retort is one that the author would agree with. The author is simply making the argument that, what IQ measures is not necessarily the same kind of intelligence as what is necessary for success in the real world. He's not actually arguing that people should be allowed to take as long as they want on the test, he's simply using that hypothetical to illustrate "what IQ tests actually measure".