Q. What is “Quinquagesima Sunday?”
A. In the old Church liturgical calendar — still observed in the Extraordinary Form of the Mass (celebrated in Latin) — the weeks immediately preceding Lent are observed as a time of preparation for the upcoming penitential season. In ancient times, Christians began their time of abstinence during this period. (By the way, the ancients gave up all animal products for the entire season of Lent — not just Fridays.)
The last three Sundays before Ash Wednesday are called Septuagesima (Latin, “seventieth”), Sexagesima (“sixtieth”) and Quinquagesima (“fiftieth”). The historical origin of these names for these particular Sundays is disputed. The earliest occurrence of the terms in liturgical literature is in the eighth-century Gelasian Sacramentary.
In the traditional Latin Mass, the Gloria is omitted on these three Sundays, just as it is throughout Lent in both the Ordinary and the Extraordinary Forms of the Mass. This omission serves as a reminder of the penitential nature of the season.