we perceive time the way we do because of what we are. while it is possible to speculate about what time might be like, outside of our experience of it, the fact remains that any attempt to verify this brings it within our experience.
i find the statement that anything actually exists to be highly speculative. it's a convenient assumption, in accordance with our experience, but that doesn't make it true, just plausible.
an alien species, with a radically different type of neurology, might experience time and space in a totally different way than we do. in certain kinds of abnormal mental states, even human beings experience time in ways that are inconsistent with the consensual views.
the degree to which all human beings are similar (genetic coding, basic biological structure, uniform molecular biological processes, etc.) make it unremarkable that we share many of the same views of the world, not only in our sensory data, but also in the sense we make out of that data. this similarity makes us all "biased", in accepting what is "common sense" (a deliberate pun).
what exists "out there", independent of what we observe, is likely to remain unknown. time is a useful construct, that helps immensely in making sense of what happens in the world, but it is not past imagining we might replace it with a more sophisticated concept at some point in the..hmmm...what we now call the future.