How is the date of the Feast of the Resurrection determined?
By CopticBot.ai (Coptic Space Inc.) · Last reviewed 2026-10-10
The calculation of the date of the Feast of the Resurrection is based on the "Epact system", a mathematical and astronomical method established by the School of Alexandria.
In the early centuries of Christianity, there was significant disagreement regarding when to celebrate Easter. Some, known as the Quartodecimans, followed the Jewish practice of celebrating on the 14th of Nisan, regardless of the day of the week. To resolve this and preserve the truth of the Resurrection, the Council of Nicaea (325 AD) tasked the Coptic Pope—then St. Alexander of Alexandria—with determining the date annually for the entire Christian world, as the Alexandrians were renowned for their expertise in astronomy and mathematics.
The date of the Resurrection is determined by four specific criteria:
1. It Must Be a Sunday
Because the Resurrection of our Lord occurred on "the first day of the week," the Coptic Orthodox Church only celebrates the Feast on a Sunday.
2. It Must Follow the Vernal Equinox
The Feast must occur after the Spring Equinox (March 21st on the Julian/Coptic calendar system). This ensures that the celebration of Life (the Resurrection) coincides with the season when light begins to overcome darkness.
3. It Must Follow the First Full Moon of Spring
Following the Vernal Equinox, we look for the first full moon (the Paschal Moon). This is rooted in the symbolism of the moon reaching its full illumination, representing the light of Christ.
4. It Must Follow the Jewish Passover
This is a critical point of Coptic Orthodox theology. According to the Holy Scriptures, the Resurrection happened after the Jewish Passover. Therefore, the Orthodox Church strictly maintains that the Christian Pascha must never precede or coincide with the Jewish Passover. This distinguishes the true Church from Western denominations (Catholics and Protestants) who, by following the Gregorian calendar, sometimes celebrate before the Jews, which is a historical and biblical impossibility.
The Role of the Coptic Pope
Every year, the Pope of Alexandria would send out "Festal Letters" to all other Apostolic Sees (like Rome, Antioch, and Constantinople), informing them of the date of the Resurrection based on these calculations. This is why the Coptic Pope is historically titled the "Ecumenical Judge."
Summary of the Process
- Identify the Vernal Equinox (March 21).
- Wait for the next Full Moon.
- The following Sunday is a potential date for the Feast.
- If that Sunday falls during or before the Jewish Passover, the Feast is moved to the following Sunday.
This precise system ensures that we adhere to the biblical chronology and the tradition handed down by the Holy Fathers of the Council of Nicaea, preserving the integrity of the Coptic Orthodox faith against the modern changes made by those who departed from the ancient canons.