If you haven't cut it open, I'd say a good four or five days, if not longer. If it's cut open and dressed, well, it depends on what you dressed it with, but I'd venture no more than a couple of days. To refrigerate a whole one, I'd rub the skin down with a little oil, wrap it in foil and refrigerate; then you can bring it out (or them, if there are several), put them in a cold oven, and reheat slowly at about 325 degrees. They should be like "new."