Maslenitsa at Mid-Hudson Russian Community Association. Maslenitsa, also known as Butter Week, Crepe week, or Cheesefare Week, is an Eastern Slavic religious and folk holiday which has retained a number of elements of Slavic mythology in its ritual. It is celebrated during the last week before Great Lent; that is, the eighth week before Eastern Orthodox Pascha.The date of Maslenitsa changes every year, depending on the date of the celebration of Easter. The traditional attributes of the Maslenitsa celebration are the Maslenitsa effigy, sleigh rides, and festivities. Russians bake bliny and flatbread, while Belarusians and Ukrainians cook pierogi and syrniki.