We don't even know if our universe is the only one, nor if it has such a great significance as we like to think it is. Maybe we're nothing but a mere particle in the great spectacle we call life haha.
Time may have always existed, yet it could be just an illusion. It could even be just another sophisticated invention that some scientist made. It might not even exist, which could show that the universe was made just now. Time is a very complex thing. The only thing we might know about how it effects energy and matter. We break it up into small intervals (seconds, minutes, ect.) for measurements, and we see how and how much things change in those intervals, so time could also be, essentially, just a cause-and-effect chain.
Nonetheless, time could be anyone of these things, but we really don't know. The only thing we can know is what other people's opinions on what time actually is are.
Space and time are inseparable and directly related to each other. Time could not exist until the universe came into existence.
The *measurement* of time is an invention by humans (and if other intelligence exist, probably by them too).
We use time to measure the intervals between events. If there are no events, then there is no time.