I don't know the opening hour but I know they close early. Around 6 or 7. We always went for lunch. That was last summer. Don't know if they change during the year.
I was wondering mainly if they would be open by 7am or earlier since I wanted to get bkfst there before MM.
That is too bad they close early b/c I have heard great reviews about that place.
I found this by searching but based on it and comments here I would say you may need to call for hours when you are there.
currently open daily 6am to 10pm (SEASON)
during the off-season, open Sunday through Thursday from 7am to 7pm
and open Friday and Saturday from 7am to 9pm
note that hours vary depending on the season (and Disney's whim, apparently)