There is no fundamental "time" in the universe. The Block Universe seems most likely.
The "Time" we perceive is an illusion created by the mechanics of our memory system.
Somebody said that entropy is the only one way arrow in physics. That is wrong. The essential one-way arrow in classical physics is inertial motion. Isaac Newton, a genius, worked with what he had available, which was a clock. He defined the magnitude of motion, speed, as distance traveled over time. This definition was adequate for the scale in which Newton was experimenting. At a later date, the concept of energy was added. Energy and time have the same problem, they are not physical quantities. They are only relative quantities. The fundamental motion, with its variable magnitude speed, is what both time and energy relate to. Set aside both time and energy as they are somewhat useful, but do not physically exist. Now (in perceived time) I ask you to also set aside the association of motion with change. From the point of view of matter moving inertially, nothing changes. Location translations change nothing. Within the block universe, the total quantity of motion is conserved. (This replaces the "conservation of energy".) Quantities of motion transfer readily from one piece of matter to another piece. Direction is not conserved due to radial motion. I don't have a clue how breadth and pull enable spinning. As Newton saw, time is the travel between one location and another---as an external observer sees it. Much later, Einstein pointed out that that view was relative, not absolute. Motion, which by itself changes nothing, is unidirectional, until the matter with a quantity of motion bumps something. I could say a piece of matter has some speed, but that seems even more confusing to me.
It takes two or more material objects (this includes fields) interacting to transfer quantities of motion and alter directions. The vectors of the objects as they approach and exit this bump (acceleration event) point to an absolute location in space. The size of this location varies because matter is squishy and bumps end up spread out over some space. Now we have an unchanging space with absolute locations and internal matter which moves and changes at event locations. The block universe.
Memory devices, such as Thomas Edison's phonograph, have a sensor/motivator, a marker, some substrate to mark, and an added motion to spread the marks apart. All memory devices have these functional components. Time as we perceive it is the space between marks on a substrate, or the distance traveled between marks. We perceive flowing time due to the added unidirectional motion component. The added motion component replaying the memory device you are looking at, printed letters and words on a page, is the movement of your eyes scanning as you read. The replaying of the marked events gives the impression of a "past" persisting beyond the original events. The future is imagined events experienced only in a mind. The present would be where the marker is on the substrate. The sequence and simultaneity of events is established by the added motion. We experience direct input and replays together and record that experience to be replayed and processed further as a conscious experience.
Our sensors, our brains, our minds, respond to and process only bumps, non-destructive acceleration interactions. We have no way to directly sense motion between interactions. We must infer motion from the arrangement and sequence of recorded bumps.
Time is observed travel between locations and Time is an illusion created by memory recordings. A real relationship and an emergent relationship. Maybe we should change our definitions to recognize that we're dealing with two different kinds of "time" ? Neither time is a fundamental feature of the universe.
This all seems obvious to me, once it has been pointed out. If it seems less obvious to you, I can provide evidence and arguments for all parts of this brief, declarative presentation upon request.
