Ranking of Liturgical Days in The Roman Rite - Ferias

Ferias

In addition to his division of festal days and Sundays, Pope John XXIII introduced a division of ferias into four classes:

• First-class ferias, outranking all feasts: Ash Wednesday and all the weekdays of Holy Week.
• Second-class ferias, outranking local second-class feasts: ferias of Advent from 17 December to 23 December, and Ember Days of Advent, Lent and September.
• Third-class ferias: ferias in Lent from Thursday after Ash Wednesday to Saturday before the Second Sunday of the Passion (Palm Sunday) except Ember Days (these outranked third-class feasts), and ferias in Advent up to 16 December except Ember Days (these were outranked by third-class feasts).
• Fourth-class ferias: all other ferias

Before that, ferias were either "major" or "minor". The major, which must have at least a commemoration, even on the highest feasts, were those of Advent and Lent, the Ember days, and the Monday of Rogation week; the others were called minor. Of the major ferias Ash Wednesday and the days of Holy Week were privileged, so that their office must be taken, no matter what feast might occur.

Ember days are four separate sets of three days within the same week — specifically, the Wednesday, Friday, and Saturday — roughly equidistant in the circuit of the year, that were formerly set aside for fasting and prayer. These days set apart for special prayer and fasting were considered especially suitable for the ordination of clergy. The Ember Days are known in Latin as quatuor tempora (the "four seasons"), or jejunia quatuor temporum ("fasts of the four seasons"). They occur in the weeks between the third and fourth Sundays of Advent, between the first and second Sundays of Lent, between Pentecost and Trinity Sunday, and beginning the first Wednesday after the Exaltation of the Holy Cross (September 14), which is between the liturgical third and fourth Sundays of September.

Rogation Days are, in the calendar of the Western Church, four days traditionally set apart for solemn processions to invoke God's mercy. They are April 25, the Major Rogation (or Greater Litanies), coinciding with St. Mark's Day (but transferred to the following Tuesday if they fell on Easter); and the three days preceding Ascension Thursday, the Minor Rogations (or Lesser Litanies). These are indicated below in the main body of the calendar and in the Movable Feasts section.