Mecyatseslov is the Orthodox church calendar, church service book with indication of Saint memory days, church fetes during the year.

As a book Mecyatseslov can consist of short hagiographies put in order of annual circle. In this case Mecyatseslov coincides with sinaksar’ (Collection of hagiographies).

Mecyatseslovs can contain troparions and kondaks to saints. Troparion is a short hymn of one stanza, or organised in more complex forms as series of stanzas. Kondak is a short religious song that contains praise to Christ, the Mother of God, a saint or a church fete.

Mecyatseslov is in sluzhbnik and in tipikon. Sluzhebnik is the Orthodox church service book which contains texts of church service for every day.

Tipikon is the Church charter. Each name that is put down to the calendar belongs to a sainted by the Church.

In the Orthodox church Mecyatseslov is a part of the following church service books: sluzhebnik, apostol, mineya, tipikon; it can contain information about features of church service in any day.

Russian folk agricultural mecyatseslov (calendar) was created on the basis of the Church mecyatseslov. Christian holy days were interpreted in accordance with work on the land. Religious rites, rituals, popular beliefs were included into the mecyatseslov. Christian saints became magic patrons, protectors, guardians of a human being, a house, domestic animals, agricultural work and crafts.