Why does Lent start on a Wednesday and not on a Sunday?

The beginning of Lent can appear strange to some people, as it begins not on a Sunday, but on a Wednesday.

The season of Advent, for example, always starts on a Sunday. This is also the case for Easter, which technically begins on Easter Sunday (the Easter Vigil the night before is part of Sunday).

Lent, on the other hand, breaks the mold and begins in the middle of the week. Why is that?

One of the primary reasons why Lent in the Roman Rite begins on a Wednesday is the calculation of the 40 days of Lent.

If you count each calendar day, Easter is 46 days after Ash Wednesday.

The six Sundays in Lent are not considered part of the official Lenten fast (every Sunday is a special remembrance of the Resurrection of Christ), and so if you subtract six from 46, you get the famous 40 days of Lent.

Initially Lent did not start on a Wednesday and in the early Church, Lent wasn't even a lengthy season. This was because Christians were persecuted for several centuries and did not have the time to set down liturgical rules.

St. Irenaeus, during the 2nd century, wrote a letter to the pope at the time about the variety of fasts before Easter.

It wasn’t until after the Council of Nicea in the year 325 that Lent was widely established as a 40-day fast. The legalization of Christianity allowed for a more public celebration of fasting and the bishops were finally able to begin the process of uniting under the Bishop of Rome in all things, including liturgical disciplines.

In addition to the 40 days of Lent, some Christians celebrate a kind of "pre-Lent" that extends the seasons of prayer and fasting to a total of 70 days.

The liturgical discipline is usually called Septuagesima (from the Latin word meaning “seventieth”), and begins on the ninth Sunday before Easter. It is classified as a “pre-Lenten” season and included in the Easter Cycle in the liturgical year.

The practice dates back at least to the 8th century and primarily consists of three Sundays that precede the beginning of Lent (Septuagesima, Sexagesima, and Quinquagesima, from the Latin for the 70th, 60th, and 50th days before Easter). The “40th” day is called Quadragesima Sunday and occurs after Ash Wednesday. Included in this practice is the wearing of violet vestments and the omission of the Gloria and Alleluia in the liturgy.

This particular season continues to be practiced by those who follow the calendar of the Extraordinary Form of the Roman Rite, and some Eastern churches have a similar pre-Lenten season.