How do you think time exists?

There are a lot of different ways to think about time: from a four dimensional perspective, a more traditional view of linear time, and some even say time doesn’t exist at all.

I don’t really have a consistent (or at least not fully developed) idea of time but it’s one of those fun things to think about. I like to think that time is the gradual expansion of the totality of facts; that the past is absolutely determined and the future is open (and possibly indeterminable).

What does everyone think about time?