From the Gelasian Sacramentary (7th Century) until the calendar reforms of Vatican II, the eighth Sunday before Easter was called “Sexagesima”. Sexagesima was a term already used in the Fourth Council of Orleans in 541. The Ordo Romanus, Alcuin, and others count the Sexagesima (60 days) from this day to Wednesday after Easter.
I’m still interested in hearing responses to my concept that the old church year calendar and lectionary may have connected more with the Jewish one. See Septuagesima.