Astronomy and Liturgy: the Symbolic Meanings of the Date of Easter

Few things, outside of doctrinal questions, have created so much dissension in the Church as the question of when Easter is to be celebrated.

From One Peter Five

By Robert Lazu Kmita, PhD

No gesture or liturgical object is without symbolic (i.e., mystical) significance.

Once the First Council of Nicaea (325) concluded, the rule for determining the date of Easter was established: “Easter is to be celebrated on the first Sunday after the Paschal full moon after the vernal equinox.” What is the symbolic significance of these astronomical reference events?

Father Hesse’s Joke

Many years ago, Father Gregory Hesse (1953–2006), a Chestertonian by spirit, was asked by some of his listeners how they should relate to the Priestly Fraternity of Saint Pius X. Naturally, being a true lover of Tradition, the Father encouraged them without hesitation to attend the Society’s Masses and, if possible, become part of their communities.

However, he also warned—humorously—that the members of the Society had one major flaw: “They are boring.” He explained that their “boring” nature stems from the fact that SSPX priests always teach the same revealed doctrines that Christianity has always passed down—from our Lord Jesus Christ and the Apostles to the present day.

Indeed, the dogmatic, moral, liturgical, and sacramental teachings of Christianity have never changed. Nor will they ever. That’s why, Father Hesse said, the members of the Society of Saint Pius X are “boring:” because they transmit only what has always and everywhere been taught by the Catholic Church. Of course, behind the Father’s humor was a sincere praise of the exceptional role the priestly fraternity founded by Archbishop Marcel Lefebvre plays in preserving Christian Tradition.

Against the Mmodernist and neo-Mmodernist mentality, the Church has never worked with transitional or volatile categories. Reflecting the perfection of the absolute divine intellect and the eternity of the everlasting life we are called to, dogmas are and will always remain the same. While their understanding may deepen, there will never be any discontinuity between what our God, Jesus Christ, taught 2000 years ago and what His Church teaches today. Likewise, we can be confident that the same teachings will be passed on 2000 years from now—and so on, until the end of the world.

The same applies to God’s moral laws and the behavior fitting them—they will always remain the same. The principles of modesty in dress, for instance, will never change—no matter how many fashion trends pass through the stormy history of our fallen world. Concretely, what the Church proposes—whether dogmatically, morally, or liturgically—is a foretaste of the immutability and eternity of the beatific vision, where all will be forever fixed under the influence of the Good (while Evil, of course, will be completely and definitively excluded).

The Liturgical Calendar and Eternity

As for the liturgical dimension of Church life, it reflects eternity through the repetitive—“circular,” we might say—nature of the religious feasts. Among these, the Feast of the Resurrection, closely tied to Pentecost, is without a doubt the most important. For over two thousand years, it has offered us the chance to reflect upon and take part in both the Passion and Crucifixion of our Savior Jesus Christ and the mystery of His glorious Resurrection from the dead. It is no coincidence, then, that the determination of the date of Easter has always been one of the most important ecclesial matters discussed.

This issue was so significant that the German historian Karl Joseph Hefele (1809–1893) dedicated an entire section of his monumental work Conciliengeschichte (A History of the Councils of the Church, 1855–1856) to its exposition.[1] What I want to highlight in this article is the final conclusion of this long debate, which was only reached at the First Council of Nicaea in 325 AD. As is well known from the famous formula “Paschal Full Moon,” the date of Easter—unlike Christmas, which is fixed—is determined based on specific astronomical events as follows:

Easter is to be celebrated on the first Sunday after the Paschal full moon after the vernal equinox.

According to the oldest and most venerable traditions, those tasked with establishing these dates were the renowned Alexandrian Christian astronomers, and the point of reference for their observations was—naturally—Jerusalem. What has fascinated me ever since I discovered this Easter rule 35 years ago is of the same nature as the wonder I felt when I saw that some of the Church Fathers assigned deep spiritual, non-astrological meanings to the zodiac signs. Essentially, the astronomical events used as references for calculating the date of Easter are true symbols, interpreted in a way that conveys the essence of our justification and salvation through the crucified Jesus.

In our Church, no gesture or liturgical object is without symbolic (i.e., mystical) significance. From the Liturgy to the simplest gestures performed by the priests and faithful in their domestic worship (like the sign of the Holy Cross), each element in the vast traditional liturgical structure has its own symbolic meaning. All of this fits within the liturgical time structured by the Church calendar.

The church year is an icon of eternity, a fact indicated by the repetition of the liturgical cycles. The yearly recurrence of the Christian feasts symbolizes the permanence proper to eternity. Each moment in the liturgical year holds profound anagogical (mystical) meaning. Regarding the Feast of the Resurrection, we’ve seen which astronomical markers determine its date: the vernal equinox and the lunar phases. The correlation between liturgical and astronomical events is based on the principle of symbolic correspondence: Church—Man—Cosmos, as explained by Saint Maximus the Confessor in his work Mystagogy.[2] To understand the importance of these astronomical reference points, we must explore their spiritual meanings.

The Vernal Equinox

Throughout the astronomical year, there are two moments—spring and autumn—when day and night are (approximately) equal: the equinoxes. For the Church Fathers, day symbolizes the very Person of Jesus Christ, as we learn from the writings of Ambrose and Augustine. Day also symbolizes the Church, as stated by Methodius of Olympus, for example.[3]

Night and darkness, by contrast, signify both the kingdom of evil and its ruler, the fallen angel Satan. The equinox, seen as the moment of restored balance between day and night, light and darkness, primarily symbolizes the state of the world after the Resurrection. If until then “the whole world is seated in wickedness” (1 John 5: 19), from that moment forward humanity was (potentially) freed and truly able to choose between Light and Darkness—a choice that was not truly possible before.

Thus, the symbolism of the equinox—related to the fact that after the spring equinox, daylight begins to grow unstoppably—is also a sign of hope: God’s light is gradually overcoming darkness. This shows us, often contrary to the appearances of an aging and sinful world heading toward its end, that after the Resurrection of Oour Lord Jesus Christ, the light of faith will conquer the darkness of ignorance, and the Kingdom of Heaven will replace the kingdom of evil.

The Moon Phases

Alongside the sun, the moon is one of the celestial bodies loaded with symbolic and mystical meaning. Its significance is revealed by Mircea Eliade, in his monumental Traité d’histoire des religions (Patterns in Comparative Religion, 1949), where he writes:

The sun remains always the same, unchanging, with no ‘becoming.’ The moon, by contrast, is a celestial body that grows, wanes, and disappears—a celestial body whose life is subject to the universal law of becoming, of birth and death. Like man, the moon experiences a dramatic ‘history;’ its decline, like man’s, ends in death. For three nights in a row, the starry sky remains without the moon. But this ‘death’ is followed by a rebirth: the ‘new moon.’[4]

Associated with the human condition—marked by birth, life, and death—the moon symbolizes humanity itself. Among its phases, the full moon represents the new condition of humanity assumed by the Resurrected Jesus Christ. The fact that the second Person of the Holy Trinity, God the Son, is—according to the Creed—seated at the right hand of the Father, uniting in His Person both divine and human natures, is a reality we can never contemplate enough. Moreover, the Holy Virgin Mary, the “New Eve,” is the best image of this immaculate human nature, through which divine grace flows to us, the baptized, who are “members” of Christ’s mystical Body—the Church.

Without exhausting the symbolic meanings of the astronomical phenomena used to determine the date of Easter, I believe the points presented here justify the conclusion that there exists a necessary symbolic relationship between liturgical events and celestial bodies. This way of understanding the connection between the Church and the Cosmos is specific to the “astronomy” of the Church Fathers, in whose vision the entire universe is a great temple, where men and angels are meant to continually adore their Creator in a Cosmic Liturgy.

Photo by Milan Ihl on Unsplash

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[1] Titled “Synods concerning the Feast of Easter,” this section is found in the English edition as follows: Karl Joseph von Hefele, A History of the Christian Councils from the Original Documents, Vol.I: To the close of the Council of Nicea, A.D. 325,  T.&T. Clark, 1871, pp. 80-83.

[2] A complete translation is signed by Jonathan J. Armstrong: Saint Maximus the Confessor, On the Ecclesiastical Mystagogy, Saint Vladimir’s Seminary Press, 2019.

[3] All the quotations from the Holy Fathers regarding the symbolism of light/sun are anthologized by the Cardinal Jean Daniélou in his study “Les douze apôtres et le zodiaque,” in Les Symboles chrétiens primitifs, Paris, Editions du Seuil, 1961, pp. 131-142.

[4] Mircea Eliade, Tratat de istorie a religiilor, București: Editura Humanitas, 1992, p. 155.