Time cannot be conceived as being linear. A linear conception or explanation of time offers the prospect and idea of time being composed of units of time (i.e., a moment), and these units come one after the other, in progression. After moment X comes Y, and after Y comes Z, and it goes on as such. This idea of time, though at first view coherent, does not hold for the fact that within the image of a line of time upon which moments are placed, that is, in which each event comes after the other, there exists the possibility of the dissociation of a moment from the aggregate of time. Within this idea of linear time, a moment would have to logically exist independent, as it is a unit composing a stretching row stitched together. A moment Z would have to be able to exist by itself, detached from moment Y, and as such we would have to say that “X - Z” would be a true progression. The very fact that this is possible negates causality, because it proposes that moments can be abstracted from the whole. It gives us the image that time is a series of events with no relation between them, and coincidentally this series of events is perfectly coherent. The reason why time cannot be seen as a simple, stretching progression is that no moment can be dissociated from another, as they are intrinsically part of what the “whole” of time is. The idea of a linear time that progresses one moment after the other, as if the past is abandoned behind and we walk towards the future (simple as!), negates the idea that time can even exist as a coherent thing.
Time needs to be regarded as an aggregate. Now, that does not mean time is static but rather it is unfinished. What we have, what we are really talking about when we invoke the name of time is the experience of the formation of time, or just the experience of time. The experience of time is not infinite, as the universe is not built within this experience, it is not a structure in which the universe is understood, but it is part of the universe. Time is immanent, and it is intrinsically tied to the universe as it comes from within it. The logical conclusion to this is that, upon the death of the universe, there could be no more experience of time. The experience of time is finite as it only can exist to measure the universe (or rather, the changes within that one). Time ceases to exist as soon as there is nothing more to measure. Thus, the experience is finite; it is a thing to be consumed
At the end, time, as the thing itself, is an image. Time is nothing but an image, a representation of the universe as it is dead, in its final and static stage. It is the unchangeable reflection of the universe at its finality. Each moment is simply a layered addition; more and more transparent and infinitely thin sheets of “moments” which compose our idea of time are added to the aggregate of time in itself. The experience of time is not a linear construction leading us to the infinite but rather the conception, as in the birth of time in its totality. The experience of time is thus not what time is, but rather what time is becoming, at each moment changing and converging towards a single point. When we talk about time, we are not talking about what the whole of time is but rather the experience of the construction of true time!
As such the end of time is determined: It is the death of the universe. The aggregate of what time is ends up just being the expression of the steps that were necessary for the conception of this death. It does not say anything about the quality of the steps, though. 1 - 1 and (2 + 3853) - (34695 / 9) both end up being just 0, their result is both null, but the components, the steps and parts of the operations are different. This analogy is not satisfying enough, though: you could always add as many steps, making time as infinite as an operation that unrolls forever. Time is moreso like a painting; adding purple to green and adding blue and red to green both lead to the same end, which is gray. The last image of the universe, that is, the totality of time can be achieved through several different paths. In the idea of the painting, you could add as many colours and try to stray the painting away from the final product all you wish, but eventually the confusion and saturation of the colours would lead to a final product no different than mixing all the colours together.
Time, then, does not have a duration expressed by time: It is impossible to say whether the experience of time will end in “10 million years” or “100 billion years”. The steps, the elements which form time are irrelevant in their identity as long as they give the final product of time. The whole of the picture is always changing. The whole of time as of right now is always changed, and the experience of time as present is only the experience of a boundary between experienced time that has elapsed and experienced time that we have left.
Time can only be defined as the changes existent between moments. Once no changes are left, the experience of time is over, and we have reached the stage of true time, the illustration of the dead universe in all the glory of its staticity.
In a final, more loyal analogy, time is like a movie. This is a movie whose ending is known, but the scenes that lead to it are, in a sense, unknown. They are though tied together, they are necessary for the movie to be a movie, and be the movie it is. This is an extensive movie, an autobiography of this Universe.
With this I say: Enjoy the show. You cannot stay after the credits.