In Slovenia Saint Martin's day is celebrated as "The day that cider is transformed to the wine".
It is usually celebrated with traditional "St. Martin's dinner" - goose, red cooked cabbage, 'mlinci' (don't know English word for it - side dish from flour, eggs, oil, ... similar to pasta). and chestnuts.
Of course there is also this year's new wine that goes with all that.
I know I will not be hungry or thirsty today