Dating of Pascha (Easter) in the Orthodox Church

My beloved spiritual children in Christ Our Only True God and Our Only True Savior,


One of the most frequent questions asked by and to Orthodox Christians is "Why does the Orthodox Church celebrate Pascha (Easter) on a different day than other Christians?" This difference has a long history related to Christianity itself, the complex nature of calendars, and the use of astronomical data.

Almost from the very beginning of the existence of the Christian Church, the issue regarding the date of our Lord's death and Resurrection presented variations. Although the New Testament relates these events to the Jewish Passover, the details of this relationship are not clear. On the one hand, the tradition of the Gospels of Matthew, Mark, and Luke identifies the Lord's Mystical (Last) Supper with His disciples as a Passover meal. This would place the death of our Lord on the day after the Passover. On the other hand, the tradition of the Gospel of Saint John situates the death of our Lord at the very hour the paschal lambs were sacrificed on the day of the Passover itself. This variation in the interpretation of the Holy Scripture led to two different practices. The one observed Pascha on the day of Passover, regardless of the day of the week, that is a fixed date. The other observed it on the Sunday following Passover. By the 4th century, the latter practice prevailed throughout the Church universally; nevertheless, differences continued to exist.

In response to this ongoing problem the First Ecumenical Council, convened at Nicaea in 325 A.D., took up the issue. It determined that Pascha (Easter) should be celebrated on the Sunday that follows the first full moon after the vernal equinox--the actual beginning of spring. If the full moon happens to fall on a Sunday, Pascha (Easter) is observed the following Sunday. The day taken to be the invariable date of the vernal equinox is March 21st. Hence, the determination of the date of Pascha (Easter) is governed by a process dependent on the vernal equinox and the phase of the moon.

Another factor that figures prominently in determining the date of Pascha (Easter) is the date of the Jewish Passover. Originally was celebrated on the first full moon after the vernal equinox. Christians, therefore, celebrated Pascha (Easter) according to the same calculation--that is, on the first Sunday after the full moon following the vernal equinox. The correlation between the date of Pascha and the date of Passover is clear. Our Lord's Death and Resurrection coincided with Passover, thereby assuring a secure point of reference in time. This assurance lasted, however, only for a short time.

Events in Jewish history contributing to the dispersion of the Jews had, as a consequence, a departure from the way Passover was reckoned at the time of our Lord's death and Resurrection. This caused the Passover to precede the vernal equinox in some years. It was, in fact, this anomaly that led to the condemnation reflected in Canon 1 of Antioch (330 A.D.) and Canon 7 of the Holy Apostles (late 4th century) of those who celebrate Pascha "with the Jews". The purpose of this condemnation was to prevent Christians from taking into account this calculation of Passover in determining the date of Pascha (Easter).

Most Christians eventually ceased to regulate the observance of Pascha by the Jewish Passover. Their purpose of course, was to preserve the original practice of celebrating Pascha following the vernal equinox. Thus the Council of Nicaea sought to link the principles for determining the date of Pascha to the norms for calculating Passover during our Lord's lifetime.

Despite the intervention of the Council of Nicaea, certain differences in the technicalities of regulating the date of Pascha remained even thereafter. This resulted occasionally in local variation s until, by the 6th century, a more secure mode of calculation based on astronomical data was universally accepted. This was an alternative to calculating Pascha by the Passover and consisted n the creation of so-called "paschal cycles." Each paschal corresponded to a certain number of years. Depending upon the number of years in the cycle, the full moon occurred on the same day of the year as at the beginning of the cycle with some exceptions. The more accurate the cycle, the less frequent were the exceptions. In the East, a nineteen-year cycle was eventually adopted, whereas in the West an 84 year cycle. The use of two different paschal cycles inevitably gave way to differences between the Eastern and Western Churches regarding the observance of Pascha.

A further cause for these differences was the adoption by the western church (Roman Catholic) of the Gregorian Calendar in 1582 to replace the Julian Calendar. This took place in order to adjust the discrepancy, and then observed between the paschal cycle approach to calculating Pasch and the available astronomical data. The Orthodox Church continues to base its calculation for the date of Pascha (Easter) on the Julian calendar, which was in use at the time of the First Ecumenical Council. As such, it does not take into account the 13 day difference between the Julian and Gregorian Calendars.

Practically speaking, this means that Pascha may not be celebrated before April 3rd, which was March 21st, the date of the vernal equinox. In other words, a difference of 13 days exists between the accepted date for the vernal equinox then and now.

Consequently, it is the combination of these variables that accounts for the different dates of Pascha (Easter) observed by the Orthodox Church and other Christian traditions.

A synopsis:

"The determination of the date of Pascha is governed by a computation based on the vernal equinox and the phase of the moon. According to the ruling of the First Ecumenical Synod in 325 A.D., Pascha Sunday should fall on the Sunday which follows the first full moon after the vernal equinox. If the full moon happens to fall on a Sunday, Pascha is observed the following Sunday. The day taken to be the invariable date of the vernal equinox is March 21st.

(Source: Greek Orthodox Archdiocese of America)

With agape in Christ,
+Father George