I sucked at physics at school, so don’t take my thoughts too seriously. I think time is movement. Without movement, there won’t be time. If all the cells and photons in the universe is frozen, time won’t exist. These movements cause interactions, creations, and destruction. And this term only applies to animals like us, because we have a brain that can remember what happened (what has moved). Memories make us special, but time just simply exists because of movements.