So, there's a pet name that was set to clear tomorrow, 9/15 at 3 pm, and I was all set to start trying for it early because I've heard that pet names don't clear right at 3 pm. But I really wanted the name, so I've been worrying and I happened to check the pet just a few moments ago, it was already marked inactive, and I was able to create a pet with the name (luckily it was a relatively obscure reference and not something more popular), almost a full day early.