In the liturgical calendar, Septuagesima is the Sunday marking the beginning of the season of Pre-Lent. It's date moves with the date of Easter, and it displaces what would otherwise be one of the Sundays in Epiphanytide.

The liturgical color is violet (or "purple"), though images are not veiled.

The setting of the mass is Merbecke.

The Proper of the Mass is at DWM pg. 214

The Gloria is omitted.

The Alleluias are omitted.

The Tract is sung before the Gospel.

The Preface is the Preface of Pre-Lent and Lent (DWM pg. 588)