So, recently, I've gotten to arguing about time with a few people.
As my opinion stands, time is the term we use to say that events are occurring. It is, simply, what happens between two events.
So the argument appears when you argue whether time has always existed. I say it has. Even without matter or energy to create events to be measured, time can still pass. You just don't have any way to measure it.
I find this theory to be more logical then saying that there needed to be a first cause for time since, technically, without time passing you could never reach that first cause.
A first cause for matter and energy is logical. Time, on the other hand, I don't see as logical.