The "Swabian-Alemannic" carnival begins on January 6 (Epiphany/Three Kings Day). This celebration is known as Fastnacht. Variants are Fasnet, Fasnacht or Fasent. Fastnacht is held in Baden-Württemberg, parts of Bavaria, and Alsace. Switzerland and Vorarlberg, in Austria, also hold this celebration. The festival starts on the Thursday before Ash Wednesday, known in these regions as Schmutziger Donnerstag or Fettdonnerstag. In standard German, schmutzig means "dirty", but actually the name is from the local dialect where schmutzig means "fat"; "Greasy Thursday".
This period of celebration and partying had its origin in the need to use up all remaining meat and animal products such as eggs and butter before the fasting season. The celebration of Carnival ends on "Mardi Gras" (French for "Fat Tuesday", meaning Shrove Tuesday), the day before Ash Wednesday, when the rigors of Lent's 40 days of fasting and sacrifice begin