The Menaion, from the Greek word for month, is the service book of the fixed calendar: twelve volumes, September through August, following the Byzantine church year that begins in September. Open any volume to any date and the day's liturgical furniture is there: stichera, the hymns sung at the evening psalms of Vespers and at the Praises of Matins; the canon, the long structured hymn of Matins built on nine odes; kathisma hymns sung between sections of the psalter; the apolytikion and kontakion, the short hymns that name the day's celebration; and for greater feasts, readings and litya hymns.
Every day of the year commemorates saints, and the Menaion supplies each with proper texts where the tradition has composed them; for saints without full propers, a companion volume, the General Menaion, offers template services by category, one for a martyr, one for a hierarch, one for a monastic mother, into which any name can be set. The greatest entries are the twelve great feasts and their seasons, whose services the Festal Menaion gathers for use where a parish cannot house the full set. The texts themselves are the work of centuries of hymnographers, and their sheer bulk is a fact of Orthodox life: the Menaion is by far the largest of the service books, and a full set in fine bindings is one of the marks of a well-furnished church.