In our secular calendar, there is a cycle of “seasons” (Winter, Spring, Summer, Fall). The dates associated with the four seasons of our weather are determined by specific events (i.e., winter solstice, vernal equinox, summer solstice, and autumnal equinox).
In the same way, the church year has various seasons as well. The dates for these are also linked to specific events that are significant for the church’s life and existence.
The first half of the Church Year follows the life of Christ beginning with the preparation for His coming (“Advent”). During this season, as we prepare to celebrate Jesus’ coming as a babe in Bethlehem to redeem us from our sins, we also prepare for His return in glory when He will judge both the living and the dead. This is why Advent is one of the two “pentitential” seasons of the church year when we are led to consider the depth of our sin and prompted to repent and look to Christ for salvation.
The church then considers Christ’s birth (“Christmas”) and His being revealed as the savior of all mankind, not just the Jewish nation (“Epiphany”). After this, the Church begins to focus on the reason for His coming, namely to redeem the world from sin, which occurs during the second penitential season called “Lent.”
“Holy Week” prepares us for the most important event in all of human history – the death of our Lord and Savior on Good Friday – when He sacrificed Himself as the Lamb of God in order to take away the sin of the world (John 1:29). On Easter and the weeks following, we celebrate the victory He won for us over sin, death, and the devil as we celebrate His resurrection. At the conclusion of His earthly ministry, Jesus is taken up bodily into heaven on Ascension Day and pours out His Holy Spirit on the day of Pentecost.
Through the season of “Pentecost” we look at the work of Christ in the life of the Church today as He continues to send forth His Holy Spirit through Word and Sacrament.
These dates all center around the most important date in all of human history – the date of Passover when Christ, our passover lamb, was slain for the sins of the world.
Though modern historians place emphasis on specific dates and times, ancient historians were more concerned with events and sequence. Therefore, the earliest church fathers simply asserted the facts of Jesus conception and birth without attempting to determine the fixed date of these events.
When the idea of fixed dates became more important, pious Christians estimated that Jesus died on March 25. Then, taking a cue from Jewish folk-tradition which taught that the great prophets died on the same date that they were conceived, they asserted that Jesus was conceived on that date also. Thus, the date of the Annunciation, when the Angel proclaimed to Mary that she would have a son by the power of the Holy Spirit (Luke 1:26-38) was established to be March 25. Nine months later is December 25 which, in the course of time, has been accepted by most of the church as the date on which we celebrate Christ’s birth (i.e., “Christmas Day”).
The season of Advent is counted backwards from December 25. The season of Epiphany begins 12 days after Christmas (thus the “12 days of Christmas”). The rest of the dates on the church’s calendar are calculated based on the Jewish lunar calendar and when the Jewish passover would be celebrated that year. Good Friday is set on the date that the Jewish Passover would be held according to the Jewish religious calendar established by God. The following Sunday is Easter Sunday. From there, 40 days are counted backward (excluding Sundays) to arrive at the date for Ash Wednesday. The time between Ash Wednesday and Easter Sunday is designated as the season of Lent.
On the 40th day after Easter, the church since about the 4th century has celebrated the feast of the Ascension based on Acts 1:3 which states, “He presented himself alive to them after his suffering by many proofs, appearing to them during forty days and speaking about the kingdom of God.” Additional support is found in Acts 1:5 where Jesus tells His disciples, “you will be baptized with the Holy Spirit not many days from now,” just before He is taken into heaven.
Ten days later is the day of Pentecost. This is the 50th day after Easter and coincides with the Jewish feast of booths. On this day, the church celebrates it’s “birthday” as it commemorates Christ’s outpouring of the Holy Spirit on His Apostles and they are sent into the world as His witnesses. Following Pentecost, until the beginning of Advent of the following year is the season of the Church when the emphasis in preaching and teaching is on the ongoing work of God today as He creates and sustains faith in the salvation won by the work of Jesus’. God accomplishes this among us today through Word and Sacrament as He sanctifies (sets apart and makes holy) believers in Christ and leads us to live holy lives in the world as we await the return of Christ in glory.
Historically this “second half” of the church year has been marked by counting the number of weeks since Trinity Sunday which is celebrated on the first Sunday after Pentecost. It is on Trinity Sunday that much of the Western Church uses the lengthy and lesser known “Athanasian Creed” which details the correct understanding of the Trinity as derived from the teachings of Holy Scripture. More recently, however, the church has begun to mark this time by counting the Sundays since Pentecost instead of Trinity Sunday.