They are open for breakfast, lunch and dinner - but I think the hours may extend/shorten depending on what time of year it is and how busy it is. We have definitely had dinner there, and even had a dessert-only meal there at about 8:00 p.m. or so, in the peak of the holiday season.
Anyway, I like(d) the meat loaf stack a lot - however, the last time I had it, it was not as good it was previous times I ate it. It was not very warm, they skimped on the gravy, and the onions which used to sit on top of the meat loaf were nowhere to be found, and the bread on which the meat loaf rests was different. I tried to ask the waitress if they had changed the recipe or if this was just an off night at Carnation, and she seemed unconcerned with answering. So I am reluctant to try the meat loaf again because I don't know if that is the new recipe for it or if that was just a bad night.