F serves snacks at any time, upon request. Technically you can insist on your meal being served at any time -- that is QF policy for F -- but most FAs frown on this severely and discourage unconventional meal times. As an aside, while QF has always had the terrific steak sandwich in F -- until 2 years ago, when it started disappearing from some flights -- AA has now added a steak sandwich in J on trans-Atlantic flights. Served as a snack prior to arrival, and every bit as good as the QF one (but with interesting differences -- well worth comparing the 2). So now AA J serves the same champagne as BA F and the same sandwich as QF F ... seems like AA is paying attention to Oneworld and learning from it.