Most of the texts come from the "Octoechos", which has a large collections of hymns for each weekday for each of the eight tones; during great lent and, to a lesser degree, the pre-lenten season, the "Lenten Triodion" supplements this with hymns for each day of the week for each week of that season, as does the "Pentecostarion" during the pascal season. Also, there are fixed texts for each day of the week are in the "Horologion" and "Priest's Service Book" ("e.g.", dismissals) and the Kathismata (selections from the "Psalter") are governed by the weekly cycle in conjunction with the season.