I think the parade lasts about 20 minutes or so but you do have to find a seat well before it starts, unless you don't mind standing behind people. People begin grabbing "seats" on curbs at least an hour before any parade.
That's what I was hoping. I much prefer later dinner times (myself) but the kids don't like to wait for dinner.
Good tip about getting a seat well ahead of time. I'm not looking forward to that experience -- having to wait so long to have a good spot for the little ones to see the parade.