Sulani Island Festivals - When Do They Happen?

Some occur in that little shallow wading cove, some at the "festival ground" I don't know about the other neighborhoods as my sims live in the town area. look for there to be a fishy in netting balloon on the kiosk, that is your clue there is something going on. Usually it's sometime between 6pm-12pm. But not always sometimes it's in the afternoon