Just as a typical calendar has four seasons, twelve months, fifty-two weeks, and 365 days that include holidays, solemn days, commemorative days, and days that are just "average," the Liturgical Year Calendar of the Church uses similar terms and measurements.
The Liturgical Year is also marked by special seasons—Advent, Christmas, Lent, The Triduum or Three Days, Easter, and Ordinary Time. The Liturgical Year begins on the first Sunday of Advent, which usually occurs around the beginning of December or the end of November, and ends on the feast of Christ the King.
However, the purpose of the Liturgical Year Calendar is not to mark the passage of time, but to celebrate and understand more fully the entire mystery of Jesus Christ, from his incarnation and birth until his ascension, the day of Pentecost, and the expectation of his return in glory. During the course of a year, the paschal mystery—the passion, death, resurrection, and ascension of Jesus—is viewed from different angles, in different lights.
The Liturgical Year Calendar first tells us what readings the Church has designated to be used for each day. Then it names the special feasts and commemorations celebrated during each season.
The order of the year is as follows:
Advent marks the beginning of the liturgical year. We celebrate this season for four weeks leading up to Christmas. We use this season to reflect of Jesus’ coming to us in the flesh and to prepare ourselves for His coming again.
We celebrate the coming of Christ in the flesh (or the Incarnation) for a few weeks. It begins on Christmas Eve (Dec 24) and continues through a portion of January when we celebrate His baptism.
Lent takes place in the 40 days leading up to Easter. This is a season of penance and fasting, modeled to us by Jesus Himself. Before His baptism and public ministry began, He retreated into the desert for 40 days of fasting and prayer. This season begins on Ash Wednesday and continues until the first Mass of the Triduum (Holy Thursday).
Fasting and Abstinence for Catholics in the U.S.
During Lent, Catholics in the United States abstain from meat on Ash Wednesday and on all the Fridays of Lent. They fast on Ash Wednesday and Good Friday.
To abstain from meat on Ash Wednesday and all the Fridays of Lent means to not eat meat on those days. It does not intend the omission of eggs or dairy products.
The required fast on Ash Wednesday and Good Friday involves eating only one full meal on those days. One or two smaller meals may be taken on those days, but may not total one full meal. The required fast does not allow eating anything between meals.
"All Catholics who have completed their fourteenth year are bound by the law of abstinence; all adults are bound by the law of fast up to the beginning of their sixtieth year.
Nevertheless, pastors and parents are to see to it that minors who are not bound by the law of fast and abstinence are educated in an authentic sense of penance."
– Code of Canon Law, #1252
Holy Week (Triduum)
The Triduum (three days) leading up to Easter are the most important three days in the liturgical calendar. They begin with Holy Thursday where we celebrate the institution of the Eucharist at the Last Supper. Good Friday commemorates the passion and death of Jesus. We mark this with a solemn service and increased fasting and prayer. The Easter Vigil takes place on Holy Saturday night. It is a when new members of the Church receive the sacraments for the first time and are initiated and welcomed into the Church
The Easter season celebrates Christ’s resurrection and victory over death. We celebrate this season for around 50 days (depending on the calendar year). It ends with the celebration of Pentecost, where the Holy Spirit descended upon the apostles and they went out to spread the Gospel and the ministry of the Church to all nations.
This is the season when we reflect upon the mission Jesus has given to us all. We reflect upon His teachings and example and pray that we may enter into that mission to share the gospel. We celebrate many various feasts throughout this time. Ordinary time ends with the Solemnity of Christ the King, which ends the liturgical year and sends us into Advent.
During the year, in addition to the obligatory Sunday worship, the Church also celebrates Solemnities, Feasts and Memorials, which may be on any day of the week. Some of these are considered Holy Days of Obligation where all Catholics are obliged to come together to celebrate Mass. Others are days that commemorate special events or persons that are highly revered in the tradition and history of the Church.