You don't need both bounds anyway. A countable set without a lower bound in any representation is already a paradox.

So the universe creates time?

Yes. After the heat death, nothing will ever move or change and so it the universe will remain in a frozen state. Time will have stopped.

Sine time is relative based on the observer and observed, if neither change in any way (no “work” happened and no information is exchanged, even on the level of fundamental particles (or fields/loops/strings or whatever happens to be at the bottom)), for every possible combination of observer and observer, then time has not advanced in any meaningful sense.