Given our feeble understanding of time both theories could be true. Since spacetime is a single entity, not two separate features of the universe, the eruption of space from a point is also the eruption of time.
In this way, the Big Bang does not have a time that it started, since there was no time before it began.
Our monkey brains really aren't equipped to wrassle such concepts. We try anyway =p
I see no need to concern my self about it.
It doesn't affect my life one way or the other.