What is "maslenitsa"

Maslenitsa (, , , also known as Butter Week, Crepe week, or Cheesefare Week), is an Eastern Slavic religious and folk holiday, celebrated during the last week before Great Lent, that is, the eighth week before Eastern Orthodox Pascha (Easter). Maslenitsa corresponds to the Western Christian Carnival, except that Orthodox Lent begins on a Monday instead of a Wednesday, and the Orthodox date of Easter can differ greatly from the Western Christian date.