Shrovetide begins on Septuagesima Sunday, the third Sunday before Ash Wednesday. The word shrove is the past tense of the English verb shrive, which means to obtain absolution for one’s sins by way of confession and doing penance. Thus Shrovetide gets its name from the shriving that English Christians were expected to do prior to receiving absolution immediately before Lent begins. Shrove Tuesday is the last day of “shrovetide”, somewhat analogous to the Carnival tradition that developed separately in countries of Latin Europe.
This Pre-Lenten season starts on Septuagesima Sunday, includes Sexagesima Sunday, Quinquagesima Sunday (commonly called Shrove Sunday), as well as Shrove Monday, and culminates on Shrove Tuesday. On the final day of the season, Shrove Tuesday, many traditional Christians “make a special point of self-examination, of considering what wrongs they need to repent, and what amendments of life or areas of spiritual growth they especially need to ask God’s help in dealing with.” Then, going to make a sacramental confession, they are shriven, absolved.
The liturgy of this pre-Lenten period is characterized by violet vestments (except on feasts), the omission of the Alleluia before the Gospel, and a more penitential mood. Fasting does not commence until the beginning of Lent on Ash Wednesday.
For more on the origins of Shrovetide…
For Shrovetide customs…
The Fight Between Carnival and Lent by Pieter Bruegel the Elder [1559]