Very few time-travel stories allow for both a self-consistent single universe and unlimited time-travel. That would almost invariably be an instant victory condition for the time-traveler, and likely boring to read about. That’s why we need restrictions like only six uses per day. Interestingly, there was a movie nearly a quarter century ago that belied it’s understanding of this with its silly premise.
It’s possible some younger readers/listeners haven’t seen this movie, so I’m going to fully endorse Bill & Ted’s Excellent Adventure. It is in my top-five movies to watch when you just want to watch a plain ol’ fun movie. It doesn’t take its subject matter seriously, but it is a damn fun time! And it has the advantage of carrying a very humanistic message.
It is notable in that, like the Harry Potter universe, causality points both ways (present effects having future causes). This makes for a great break-out-of-jail scene once the protagonists realize they are very nearly gods. They never use this power for anything important (it is a goofy comedy, after all) but it’s a fun introduction to the self-consistency principle.