There's only one way time can be perceived. There's a past, a present, and a future. All events must lie within those states or they are not events. I think the fact that we do perceive time is evidence that time itself exists.
Not exactly. Consider this argument:
What is the past? The past cannot be accessed, it cannot be seen, heard, smelled, tasted, or touched. The clock that says 5:00pm now doesn't tell you that a minute has passed since 4:59, it simply exists in the state 5:00 right now. Conventional common sense tells us that a minute has passed since 4:59, but that's because we make assumptions about time, like that its continuous, and passes constantly. So really, the past, if it ever existed, does not exist now, and therefore does not exist. The future is similar. We cannot access the future. Just because we think our clock will say 5:01 in a minute does not mean it will happen, the future may not ever come. The future does not exist, because it never has existed, and even if our clock does say 5:01 at some point, that is now the present, not the future. There are no past or future settings, only the present. And if we consider the present, does that exist? If we check our clock, is it exactly 5:00 right now? Or is it 5:00:01, so that 5:00:00 no longer exists? Or is it 5:00:000001? We can repeat this process to infinity, and we can see that the present does not exist, because it is infinitely small. So there is no past, present or future.
That argument is simply food for thought, though the idea that there is no past or future is not as absurd as it sounds, in my book at least. The idea that time is a form of distance holds some weight, especially when you consider the ideas of special relativity. The distance between me and a fixed point in space will always have some fixed value, and at a fixed speed will always take some fixed time to get there. Instead of saying "I am 10 feet from you" I could just as easily say "I am 3 seconds from you" if I knew my speed, and in that sense there really is no past or future, only the present distance in time. There is no future distance or past distance in the universe, because to consider those is to consider states which do not exist as far as the actual state of the universe is concerned.
Of course, this is all food for thought. I know that if I show up at 7:30am when I was supposed to be at work at 7:00am, the "time doesn't exist" excuse isn't going to work on my boss
None.