Today is Fat Thursday in Poland (Tłusty Czwartek in Polish). On this day, traditionally, people and shops make and eat pączki, Polish Donuts that are yeast dough and deep fried in fat. They are yummy. When I was young, I remember my mother making pączki each year, though in America we traditionally celebrated Shrove Tuesday, the day before Ash Wednesday.
You can learn more about Tłusty Czwartek here: http://easteuropeanfood.about.com/od/holidaysfestivals/a/paczkiday.htm. However, I here is the pertinent part:
In Poland, pączki are eaten on Fat Thursday or Tłusty Czwartek. The last six days of carnival season (karnawal) — from Tłusty Cwartek to Shrove Tuesday — are known as zapusty. Shrove Tuesday is known as Śledziówka or Herring Day when herring are eaten instead of pączki. Shrove Tuesday is also known as Ostatki, which literally means “lasts,” and refers to the last day to party hearty before Lent begins. The start of Carnival season is usually on Twelfth Night or Epiphany, Jan. 6. The traditional Polish way to celebrate Carnival is with a kulig, a horse-drawn sleigh ride through the snow and a hearty outdoor meal like bigos cooked over an open fire. Things are changing, however, and bar-hopping is taking the place of kuligs.