Liturgical days are marked using the Schneyer's system

• T = tempore
• First number: the specific Sunday/Feast
• Second number (after / ): the day of the week after the Sunday (attention: the first day of the week is Sunday; Saturday is marked as Sab).

Codes of the liturgical days for Lent (and some feast days) according to Schneyer’s system

• T16 Sunday Septuagesima
• T17 Sunday Sexagesima
• T18 Sunday Quinquagesima
• T18/4 Ash Wednesday
• T19 Sunday Invocavit [First Sunday of Lent]
• T19/2 Monday after Invocavit
• T19/3 Tuesday after Invocavit
• […]
• T19/Sab Saturday after Invocavit
• T20 Sunday Reminiscere [Second Sunday of Lent]
• T21 Sunday Oculi [Third Sunday of Lent]
• T22 Sunday Laetare [Fourth Sunday of Lent]
• T23 Sunday Judica (de Passione)
• T24 Palm Sunday
• T24/2 Monday after Palm Sunday
• T24/3 Tuesday after Palm Sunday
• T24/4 Wednesday after Palm Sunday
• T25 Holy Thursday (in coena domini)
• T26 Good Friday
• T27 In vigilia paschatis [Saturday before Easter]
• T28 Easter
• T28/2 Easter Monday
• T28/3 Tuesday after Easter
• T29 Sunday In albis
• S28 Annunciation (25 March)