Actually its really pretty simple its just old and even week, but that is the order they go in, I have no idea what festival is week 1, 2, 3 or 4. The festival starts the closest day to whenever you start your game, or install City Living. With me since I was playing an old save it started with the Humor and Hijinks festival because that was the closest day in that save. To someone else they could start with the Flea Market, but the order and time is still the same.
Edit the Festivals will always be on the same day and time and place no matter were you start in the festival line up depends on the closest festival to your save file.
For example if you start with the Romance festival on Saturday Humor and Hijinks Festival will be the coming Monday, followed by Spice festival next Monday, Flea Market that Sunday and GeekCon Tuesday and than back to the Romance Festival on Saturday.
Romance festival will always come before Humor and Hijinks Festival and Spice Festival will always come the day before the Flea market and Flea Market will always come before GeekCon