@etcetcetc00,
Time is a tricky thing, and one must separate the experience of time by sentient life and the phenomenon itself, if it even exists, to lead a coherent discussion about it.
Starting with the former, time appears linear to humans (as the prime example, not the only) because we are only able to percieve it with our senses. This gives rise to notions such as past, present and future, but in reality it is much more complicated than that. The delay between an event happening, it getting registered by our senses and then processed by our brain means that we'd technically, by the above criteria, only be able to experience the past. Its truely amazing to think that while you're walking you're actually already ahead of the place you believe you are at. The information gathered is stored though, and through comparison between experiences we can deduce, to a lesser extent atleast, the future.
The way we recall the past is also one piece of the puzzle, rats for an example do not recall an event as it happened, from start to beginning. They literally rewind their experience, recalling the most recent related memory, then the next one etc, creating a backwards sequence of the events. This alone is enough to change your personal perspective of time dramatically. It would be theoretically possible for a society with enough information gathering or processing ability to percieve all time at once, but in my opinion only if the universe is infact deterministic. Otherwise, I do not see how these beings would differentiate what is/has/will happen and what they just believe.
As for time in itself, I am in doubt it exists. Much like space, it seems only a parameter, a simple property of the universe to be reducible into lesser parts and to enable the other workings within it to function as they do. Ultimately, as the previous poster stated, the true nature of time eludes us at this point.