Septuagesima

Septuagesima (in full, Septuagesima Sunday) is the name for the ninth Sunday before Easter, the third before Ash Wednesday. The term is sometimes applied also to the period commonly called Shrovetide (the Pre-Lenten Season) that begins on this day and ends on Shrove Tuesday, the day before Ash Wednesday, when Lent begins.

The other two Sundays in this period of the liturgical year are called Sexagesima and Quinquagesima, the latter sometimes also called Shrove Sunday. The earliest date on which Septuagesima Sunday can occur is January 18 (Easter falling on March 22 in a non-leap year) and the latest is February 22 (Easter falling on April 25 in a leap year).

Septuagesima comes from the Latin word for "seventieth." Likewise, Sexagesima, Quinquagesima, and mean "sixtieth," "fiftieth," and "fortieth" respectively. The significance of this naming (according to Andrew Hughes, Medieval Manuscripts for Mass and Office [Toronto, 1982], 10) is as follows: "Septuagesima Sunday [is] so called because it falls within seventy days but more than sixty days before Easter. The next Sunday is within sixty, Sexagesima, and the next within fifty, Quinquagesima ... Falling within forty days of Easter (excluding Sundays) the next Sunday is Quadragesima." Because every Sunday recalls the resurrection of Christ, they are considered "little Easters" and not treated as days of penance. Also note that Quadragesima serves as the Latin word for the season of Lent, which (not counting Sundays) is forty days long.

Amalarius of Metz would have the name indicate a period of seventy days made up of the nine weeks to Easter plus Easter Week, which would mystically represent the seventy-year Babylonian captivity.

Septuagesima was also the day on which one could begin a forty-day Lenten fast that excluded from its observance Thursdays, Saturdays, and Sundays.

The 17-day period beginning on Septuagesima Sunday was intended to be observed as a preparation for the season of Lent, which is itself a period of spiritual preparation (for Easter). In many countries, however, Septuagesima Sunday marked and still marks the traditional start of the carnival season, culminating on Shrove Tuesday, sometimes known as Mardi Gras.

...
Wikipedia