You are thinking way too much. Forget about what you've learned. Pretend you are cave boy,.....not a thought in your head. You haven't thought about math or time or gravity or anything. You are only thinking about that cave girl and that dinner running around and how you can get each of them either on you in you.
He doesn't have a watch. In fact time hasn't even been "dreamed up" but you and I both know that there will be a moment that passes between when cave boy wants to play with cave girl and the moment he actually gets to play with cave girl.
Likewise, while cave boy is chasing his dinner with a little spear (that he dreamed up and then built) it will take a period for him to actually catch up with his goal. ("Put bunny in mouth") These moments or periods are the definition of TIME.
Did he make time up? No Did he track time? Yes, unknowingly his brain calculated how much time it would take between the moment he released his spear on a given trajectory and when it hit the bunny in the butt.
(TIME) was always there, waiting to be named and measured. That we've taken it and created the math of time is irrelevant. Our measurement of our environment is something we created to give things a value. But the environment is there regardless of how we percieve it.
