Fettisdagen is the Tuesday after the Quinquagesima

Quinquagesima

Quinquagesima is the name used in the Western Church for the Sunday before Ash Wednesday. It was also called Quinquagesima Sunday, Quinquagesimae, Estomihi, or Shrove Sunday...

 and the last day before the Christian feast

Calendar of saints

The calendar of saints is a traditional Christian method of organizing a liturgical year by associating each day with one or more saints and referring to the feast day of said saint...

; the day between Shrove Monday, and Ash Wednesday

Ash Wednesday

Ash Wednesday, in the calendar of Western Christianity, is the first day of Lent and occurs 46 days before Easter. It is a moveable fast, falling on a different date each year because it is dependent on the date of Easter...

. Because it is the last day before the Easter Feast, it has created a tradition to eat buns, so called "fastlagsbullar", "fettisdagsbullar" (Fat Tuesday Buns) or "semla

Semla

A semla or fastlagsbulle , laskiaispulla or fastelavnsbolle is a traditional pastry made in various forms in Denmark, Estonia, Finland, Latvia, Lithuania, Sweden and Norway associated with Lent and especially Shrove Monday or Shrove Tuesday.The name semla is a loan word from German Semmel,...

". The day is also called "White Tuesday" since the buns were made out of white flour.

The day is called "Mardi Gras

Mardi Gras

The terms "Mardi Gras" , "Mardi Gras season", and "Carnival season", in English, refer to events of the Carnival celebrations, beginning on or after Epiphany and culminating on the day before Ash Wednesday...

" in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

.