RORY: She [Lorelai] didn’t have lunch.
There seems to be a bit of a pattern of Lorelai skipping lunch on Fridays, perhaps because she knows she’ll be getting a good dinner at her parents’ that evening. As a result, she turns up to dinner hungry and cranky, and ready for a dramatic fight every week! Of course, it’s possible Lorelai often skips lunch on weekdays, due to her busy schedule at the inn.
The Annotated Gilmore Girls 