Well I mean the last time Nintendo did technically launch a home console outside of the fall season was the Nintendo 64 which launched in Japan in June of 1996 (actually they were aiming for a spring '96 launch after delaying past holiday '95).
The N64 was really formally first shown with games at the Shoshinkai Show (precursor to Space World) in November of 1995.
So that's basically seven months from actual unveil to launch.








