The existence of time we cannot hope to fathom normally. For 'time' does not exist. But we can at least try to understand it by looking at Time itself, what is it, what makes up Time?
Why cannot we go back and change what we have done? What keeps us moving forward, but only allowing us ability to look back? In this sense, there must be some kind of concept of time, or something that we have categorized as time. So what is it? There's no two ways though about it, there must be something that keeps us locked in the shackles of 'time'. At the same time, there is no lining existence of 'time' within reality, but rather in perception.
At this point, this is about as far as Philosophy is able to travel when it comes to 'time'. Time is not a thing of philosophy, but of science. After all, Time is a thing of nature, something unchangeable, unalterable, and must always be. But time is so elusive that it is impossible to grasp as humans. But there is one thing that can be said about time; Time is used to record what has happened and what will happen. Through this, we can make another conclusion.
Time is the release of energy.
Picture something was 'frozen in time'. When something stops moving, as to be 'frozen in time' they do not see, they do not move, their activity is halted. Their time has stopped. No cells move within them, no electrical shocks travel, they are caught 'frozen in time'. Everything is like that. If you see no activity released then you can tell time has frozen. if that's true, then the converse must also be true. If you see something frozen in time, then you know there is no activity. So, to be concise, they are one in the same.
So moving on, then the less active you are, or the more you do something distasteful, the slower time flows? Essentially yes, when you are doing something you don't like, time seems slower. That's your lessened release of energy that you are perceiving in the longer time. Respectively, if you are having fun, and time flies, your perception of time and release of energy is hastened. That time takes place within yourself, but you are aware of the outer time as well, because everything else is releasing energy as well. If nothing released energy, and there was no activity, then you can assume that 'time has frozen'. And once energy is released, then you cannot get it back, which can also be assumed from 'release of energy'.
'Time' as we know it does not exist. We believe 'Time' as the main existence, when it doesn't exist within itself. Time though, does exist, as a construct of many different components of energy and perception.