Trick question. With the big bang everything came into being, including time. Since 'before' is a temporal attribute, but time did not exist yet, the question is undefined.

Everything needs time to happen. Without time nothing happens. Nonetheless the big bang happened.
Thereby I conclude the big bang happened outside of time and could maybe be called a supertemporal event.

So I am wondering. If the big bang is an event outside of time, why would it have happened 13.8 billion years ago? How does that make sense? If it, or parts of it, happened outside of time how can you just put a date with it and be done with it? Whose to say it only banged in the past? Maybe it's still banging right now, affecting the universe not just down the "normal" route of time 13.8 billion years ago but also from an outside-of-time-position directly in the now. Maybe it's even still pumping in the past.

If the past grows and the present grows and additionally the growing past naturally flows into the present which will make the present continue to grow even further, then the growth rate is accelerating. This is Dark energy
Yes I'm high.