We were there in early April, and the parade was at 3pm. I have to admit though, we were pretty disappointed! Since it is a "Block Party", the parade stops at each "block" and they do their dancing and such at one spot. If you are right there for it and they stop in front of you by chance, you can be a part of the action- otherwise your other option is to follow behind the parade to keep up with it.
For us, it was a waste of time and a let down, as there aren't many characters.
Enjoy your time there!!