Well sure, if you parametrize with a time factor the result will be a periodic function. But you can still de-parametrize and simply have a closed loop described relationally. A parametrization of a circle usually consists of periodic functions, but that doesn't mean the circle itself is periodic. It's just there.

Also remember that "exactly the same configuration" means exactly the same configuration, of everything, including for instance your calendar, your watch, and your brain and its stored memories. So pretty much by definition there would be no record of such a thing happening. We wouldn't need another variable to encode it because we wouldn't need to encode it in the first place.