Maslenitsa

Short answer: Maslenitsa, also called Butter Week or Cheesefare Week, is an Eastern Slavic religious and folk holiday observed mostly in Russia, Ukraine and Belarus, and by their diaspora communities.

It falls in the last week before Great Lent, the eighth week before Eastern Orthodox Easter, so its date moves every year. In 2025 it ran from February 24 to March 2. In 2026 it ran from February 16 to 22. Wikipedia describes it as a Christian observance that keeps many elements of older Slavic mythology. Meat is already off the table that week for observant Orthodox Christians, but butter, cheese, eggs and other dairy are still allowed, so the signature food is blini, thin pancakes. Ukrainians and Belarusians also make varenyky and syrniki. Customs include visits to family, sleigh rides, sledding, snowball fights, the storming of a snow fortress and, in some regions, a different tradition for each day. The week ends on Forgiveness Sunday, when people ask one another's forgiveness. A straw effigy, Lady Maslenitsa, is stripped of her finery and burned in a bonfire, and the next day, Clean Monday, Lent begins. Large public celebrations faded after 1917 under Soviet state atheism, returned in a more secular form in the 1960s and 1970s, and grew again after the Soviet Union ended. Moscow has held a yearly festival near Red Square since 2002. The footage shows masked revelers in horned and antlered costumes and huge wooden towers burning in the snow in front of a crowd.