From an article published with the RWA’s Regency Chapter, The Beau Monde:

In the still largely agrarian world of the early 1800’s, fall and winter became a time to relax after harvest.  Gentry and yeoman alike could take advantage of old feasting customs that had long ago mingled with the Christian holidays.

In Fall, Parliament opened again and society returned to London.  St. Michael’s and All Angel Day, or Michaelmas, at the end of September, marked the end of a quarter year.  The end of the Celtic year itself fell on October 31, and the ancient celebration for the Celtic god Saman (also Samhain) became All Hallows Eve.  October was a month when land owners ate pheasant, partridge, duck and grouse.  Fish for meals included perch, halibut, carp, gudgeons, and shellfish.  And poachers also looked to snared hares for their pot.  Beans were still fresh, and the fruits of summer gave way to pears, apples, nuts and the last harvest of grapes.

On November 5 bonfires burned in mockery of Guy Fawkes and memory of the Gunpowder Plot to blow up Parliament.  The Feast of St. Martin, or Martinmas, fell on November 11, and St. Andrew, the patron saint of Scotland, had his day on November 30.  St. Andrew’s day also marked the beginning of Advent to celebrate the four weeks before Christmas.  In November, the landed gentry still dined on wildfowl as well as domestic poultry–which was now getting a bit old and aged.  They also had beef, venison and pork with their meals.  Fish could still be caught and served, and winter vegetables graced the dining room, including: carrots, turnips, parsnips, potatoes, leeks, cabbage, celery and lettuces.  With November, walnuts and chestnuts came into season.

More celebrations lead to Christmas Eve when the Lord of Misrule danced and the Mummers traveled to perform their pantomimes.  Then came Christmas Day, and Boxing Day on December 26, which was St. Stephen’s Day.  Boxing Day did not get its name from gift boxes, for the exchange of gifts was a German custom still new to Regency England.  Instead, Boxing Day got its name from the older tradition of it being a day in which pleadings could be placed in a box for a judge to privately review.  In December, besides beef and mutton to eat, pork and venison were served.  Goose was cooked for more than just the Christmas meal, and there would be turkey, pigeons, chicken, snipe, woodcock, larks, guinea-foul, widgeon and grouse to eat.  Cod, turbot, soul, sturgeon and eels joined the list of fish in season.  Forced asparagus added a delicacy to the usual winter vegetables.  Stored apples, pears and preserved summer fruit appeared on the better, richer tables.

Finally, celebrations mixed tradition and religion when the Twelfth Night feast arrived on January 5, which combined the Roman Saturnalia with the Feast of the Epiphany, when the three wise men were said to have paid tribute to the Baby Jesus.  Deep in winter, there was still plenty of game to eat.  Beside those wild and tame birds available in December, lobster came into season in January, as did crayfish, flounder, plaice, smelts, whiting, prawns, oysters and crab.  Broccoli made a welcome change from the other winter vegetables, as did cress, herbs, cucumbers, beets and spinach.  Preserved fruits would be running low in all but houses with large orchards, and stored apples and pears would have to serve guests until the expensive forced strawberries of February appeared.