This week is Maslenitsa or “Pancake week” in Russia. Maslenitsa is one of the oldest holidays in Russia, dating back to pagan times. It was originally a sun festival, celebrating the imminent end of winter. The holiday survived both the Christianization of Russia as well as the atheist Soviet rule. Maslenitsa is marked with celebrations and lots of Russian bliny (a type of pancake or crepe).

Link: Wikipedia article on Maslenitsa