A Reader Asks: “Why Do the Eastern Orthodox Celebrate Easter One Week Later than Roman Catholics in 2019?”

From: Mark

Pope Gregory XIII’s 1582 Decree, Inter Gravissimas
By Which the Catholic World Ceased Using the Julian Calendar
And Adopted What Is Now Called the Gregorian Calendar
Which Corrected the Slight Error that Remained
In Julius Caesar’s Reformed Calendar
Still Today Some Eastern Orthodox Sects
Retain the Julian Calendar for Religious Purposes
Thus the Difference in the Date of Easter Celebrated by Them

Why do the Eastern Orthodox Christians celebrate Easter one week later than Roman Catholics? For example, the Catholics celebrate Easter in 2019 on April 21, whereas some Eastern Orthodox sects celebrate Easter on April 28.

THE TRADITIO FATHERS REPLY.

It is a matter of the calendar used. Up until the 16th century, all Christians used the Julian calendar, promulgated by Julius Caesar in 46 B.C. to correct the woefully deficient Old Roman calendar. By the time of Pope Gregory XIII (1572-1585), however, the slight error that remained in the Julian calendar had accumulated to some ten days by 1582, when Pope Gregory introduced what is now called the Gregorian calendar into the Church. This charge also altered the calculation of the lunar cycle used to calculate the date of Easter, returning it to the method used in the early Church.

Although Catholic countries immediately adopted the Gregorian calendar, it took the next three centuries for most of the rest of the world to do so. However, some of the Eastern Orthodox sects still retain the Julian calendar for religious purposes. Thus the difference in the date of Easter celebrated by them.

Unbeknownst to virtually all Catholics, this new calculation is actually described in detail in the Missale Romanum published after the Council of Trent in the late 16th century, in the section “De Anno et Eius Partibus.” Next Sunday ask your traditional priest to show you this historic section in the altar missal.

Also unbeknownst to virtually all Catholics is a little-known Appendix to the Vatican II Anti-council’s Sacrosanctum concilium(Constitution the Sacred Liturgy), entitled “A Declaration of the Second Oecumenical Council of the Vatican on Revision of the Calendar,” in which the Anti-council says that it is willing to have a “New Calendar,” with a fixed Sunday for Easter rather than the Sunday calculated from ancient times in the Catholic Church.