"But Never Jam Today"

"It's very good jam," said the Queen. "Well, I don't want any today, at any rate." "You couldn't have it if you did want it," the Queen said. "The rule is jam tomorrow and jam yesterday but never jam today." "It must come sometimes to 'jam today,'"Alice objected. "No it can't," said the Queen. "It's jam every other day; today isn't any other day, you know." Lewis Carroll, Through the Looking Glass.