Hey Dave, sorry bout the late response, haven't checked in on this place in a while.
It's usually right around Independence Day - first week of July.
I've been to the last 3, and they were all during that long weekend.
That doesn't mean it always will happen then, but since at least 2017, that's when it was.
Most likely at the Aria, either in a convention space inside Aria, or at the PokerGo studio which is connected to the Aria building.