1). In order to be aware of the passage of time one requires stability of/access to past events in the form of a record/memory. If we had no memory of the previous moments how would we ever know there was a "then" to this "now", a "cause" to this "effect".

2). The universe shows lack of simultaneity. Due to gravity all parts of the universe experience the passage of time differently therefore how is there a unanimous "now". Even a hiker at the base of a mountain experiences slower time passage than one at the top even if infitisimally small. Your now is different to mine. When I react instantly to something you see it occur slightly afterward at a different point in "time" due to the fact we occupy different space.

3). We all live in the present. The past has never been reached nor has the future. You are always living now. You were born now and you are reading this now and you will die now. The only dividing factor is the sequence of change that is continuously occuring now. Where is time if it's always this case?

4). When does an event end? Units of time are arbitrary. The second, hour month etc are manmade repeatable units based off natural ones from astronomy and ecological cycles. It seems the only way to measure time is to particularise it as a frequency of a defined length. Otherwise it simply flows with events just blending into one another. One seamless transitional state of change.

5). Reversability. Almost all mechanism of physics are reversible and work equally well backwards as forwards. They are directionless and do not require an arrow of time. Entropy increases the disorder of energy giving us a seemingly obvious direction to time. However the dury is out on whether entropy has an opposite. Life is technically a decrease in entropy as it is the organisation of a system so perhaps consciousness plays a role in countering entropy? Gravity orders millions of chaotic mass particles into a singular one and then perhaps a black hole which further gathers energy in its light form too decreasing entropy.

6). Energy and time really describe two facets of the same thing. Energy is the ability to cause change/work and time the measure of change but they are linked inseparably to eachother. We really only require energy to cause motion in the universe as time cannot occur without energy to bring about events. You could argue it in reverse that energy is impossible without time to allow events to happen. But if you think of it as a spectrum with one end being all energy and no time and the other all time and no energy it makes more sense as differing "rates" of the same phenomenon. In the middle is the only place where you can speak of energy and time as separate entities because theres a ratio of the two. Relativity.

7). At the speed of light (speed of change/energy)... nothing changes. Time doesnt occur for pure light energy. Energy travels in an instant from the sun to earth due to time dilation and space contraction but because we exist as mass at a lower rate of change it appears to take 8 minutes. The difference in rate and quality of energy is manifested as time and space. Therefore doesnt time really only play a role when energy is mass? (not travelling at the speed of light with relativity to its surroundings - space.) and can actually interact and be set in motion by itself - "faster" "less solid" raw energy.

I'm skeptical to believe time actually exists in the universe. I believe it is a necessary concept to explain all phenomenon relative to one another across a medium which is objective and constant (both in the sense of physics but also conscious experience of the past present and future) but its convenience/utility doesnt mean it actually physical exists.

Thoughts? Happy to be corrected on some or all of my points if you can defend a contrary argument.