Today is Michaelmas, the day devoted to the Archangel Michael, chief of the angels, who threw Satan out of heaven. St. Michael is also an eschatological figure, who is supposed to play a prominent role in the end times. See a great discussion of the significance and old customs of the day in Britain, at Dark Dorset, including cooking a goose at dinner. There's a touch of ancient sacrifice to this festival: "'September, when by custom (right divine) Geese are ordained to bleed at Michael's shrine.'"
Michaelmas also marks the last day of the year for eating blackberries (which explains why an Italian friend put a picture of Bavarese alle more up on Facebook yesterday). Satan, according to religious legend, landed in a blackberry bush when he fell to earth, and cursed the berries after September 29.
September 29 is supposed to be the last day of the year to eat blackberries: Macarons alle more. Image Source: Cucinare Dolce.
Thus, the British holiday overlaps in its practical purpose with harvest festivals at this time of year, such as the secularized Thanksgiving in North America. In 2012, the BBC reported on a revival of the observance of Michaelmas:
The traditional goose meal is seeing a revived interest in the UK, the industry says, with between 5-10% of British geese now being reared for the autumn instead of Christmas, which is the traditional seasonal focus. ...
Michaelmas celebrates St Michael and all angels, which falls on 29 September for most of the UK. There are anomalies though: It's 4 October in Suffolk, and 11 October in Norfolk.
It falls near the autumn equinox and also marks a medieval festival when harvest was finished and farmers paid rent to the landowners, often offering geese as part of the exchange.
Goose fairs became popular across the country, with farmers driving their geese for miles to get to market.
The Michaelmas goose itself became associated with paying off debts, and according to folklore eating one on the day would bring financial luck for the coming year.
But over the last century "the seasons' festivals we used to have, fell out of fashion", says food writer Karen Burns-Booth, who specialises in food history and traditional recipes.
"We lost a lot of the agricultural emphasis particularly just after WWI… people became more industrialised, started to move to cities, therefore all those festivals sort of fell along the wayside." ...
Michaelmas geese tend to be leaner than their Christmas cousins, because they are slaughtered earlier and have been fed on "lovely lush spring grass", while Christmas geese fatten up during the winter, explains Mr Hegarty [chairman of the British Goose Producers].
A traditional Michaelmas goose can be roasted and served in the same way as a Christmas goose, but a number of recipes instead use seasonal ingredients such as apples and blackberries, or marrow and runner beans.