Calendar

The three Sundays prior to Ash Wednesday are not ten days apart (that would indeed be quite miraculous), but nevertheless tradition gives these three "Gesima Sundays" the prefixes of Septua (70), Sexa (60), and Quinqua (50) as a countdown toward Lent. Quinquagesima is indeed 50 days before Easter, but Sexagesima and Septua aren't quite 60 and 70. Lent itself is that 40 day period (excluding Sundays, which traditionally are not penetential) from Ash Wendnesday to the Great Vigil on Holy Saturday.

In 2012, Septuagesima falls on the Fifth Sunday after the Epiphany. In 2011, Septuagesima fell on the Seventh Sunday after the Epiphany. How can this be?

Epiphany is always on January 6, beginning immediately after the Twelve Days of Christmas (December 25 through January 5). We then have a period of "Sundays after Epiphany." However, the number of these Sundays after Epiphany varies because, beginning with Ash Wednesday, the church calendar switches over to its paschal cycle, which is determined not by fixed calendar dates (such as December 25, January 6 and February 2), but rather by the movable date of Easter, which the First Council of Nicaea in AD 325 established as the first Sunday after the full moon (the Paschal Full Moon) following the northern hemisphere's vernal equinox. The date of Easter can fall as early as March 22 or as late as April 25. That's quite a wide range.

Therefore, the "Sundays after the Epiphany" also have a wide range, because they have to fill the gap between the fixed date of Epiphany (January 6) through to the moveable date of Ash Wednesday (always 40 days before Easter, excluding Sundays). Sometimes there are only five Sundays after the Epiphany; sometimes there are nine. However many there are, the last three are always the gesima Sundays.

Collect:

O God, the strength of all those who put their trust in thee: Mercifully accept our prayers; and because, through the weakness of our mortal nature, we can do no good thing without thee, grant us the help of thy grace, that in keeping thy commandments we may please thee both in will and deed; through Jesus Christ our Lord, who liveth and reigneth with thee and the Holy Spirit, one God, for ever and ever. Amen.