Triodion

The "Triodion" ( _el. Τριῴδιον, "Triōdion"; Slavonic: Постнаѧ Трїωдь, "Postnaya Triod"; _ro. Triodul), also called the Lenten Triodion (Τριῴδιον κατανυκτικόν, "Triodion katanuktikon", Albanian: "Triod/Triodi"), is the liturgical book used by the Eastern Orthodox and Eastern Catholic Churches of Byzantine rite during Great Lent and the preparatory weeks leading up to it.

Many canons in the Triodion contain only three canticles or odes, hence the name "Triodion", meaning "Book of the Three Odes". The period which the book covers extends from the Sunday of the Publican and Pharisee (the tenth before Pascha (Easter): twenty-two days before the beginning of Great Lent), and concludes with Great Saturday. During this period, the services of the Divine Liturgy and the Canonical hours undergo profound changes. The Triodion contains propers (seasonal material) for:

* the Pre-Lenten period
* the Forty Days of Great Lent itself
* Lazarus Saturday and Palm Sunday
* Great and Holy Week (up to and including the Midnight Office of Great and Holy Saturday)

In the edition of the Lenten Triodion used by the Old Believers and those who follow the Ruthenian recension, the contents of the Triodion end with the service of Lazarus Saturday and do not contain the services of Holy Week, which are to be found in the Pentecostarion.

See also

* Pentecostarion - the companion volume for the Easter period.
* Paschal cycle