The day after Disneyland opened. The reason being is that the park got grilled in the papers the next day. Nothing went right that day. The water fountains didn't work. It was a scorcher of a day, the pavement hadn't hardened yet.
I know we fantasize about how that day would have gone as Disney fans but the truth is it was a disaster (although I would have loved to have been there still).
So despite Walt being an optimistic person as we all know how do you think he reacted on the inside? The future of the company rested on the success of Disneyland. Did he have any doubts about the place? He didn't know what we all know now, 58 years later there are message boards just to talk about his park, but in 1955 he didn't know this. How nervous would he have been? Or was he not nervous at all and was he patient and confident his park would thrive?