The common Rodnover ritual calendar is based on the Slavic folk tradition, whose crucial events are the four solstices and equinoxes set in the four phases of the year. Slavic Native Faith has been described as following "the cycles of nature", of the seasons of the year. A festival that is believed to be the most important by many Rodnovers is that of the summer solstice, the "Kupala" Night (June 23–24), although also important are the winter solstice festival "Karachun" and "Koliada" (December 24–25), and the spring equinox festival Shrovetide—called "Komoeditsa" or "Maslenitsa" (March 24). Festivals celebrated in spring include the Day of Yarilo and the "Krasnaya Gorka" (literally "Red Hill", celebrated between April 30–May 1), the latter dedicated to ancestor worship; while in autumn Rodnovers celebrate the Day of Marzanna and that of Mokosh (November 10). Other festivals include the Days of Veles (multiple, in January and February) and the Day of Perun (August 2), the latter considered to be the most important holiday of the year by some Rodnover organisations. The Anastasians also celebrate the Day of the Earth on July 23 with characteristic rituals prescribed in their movement's books.