Will Catholics and Orthodox Settle on a Common Easter Date?

The Hope for Ecumenical Unity Includes the Desire for a Reconciliation of the Gregorian and Julian Calendar


The Ecumenical Patriarch of Constantinople Bartholomew kisses the pectoral cross of Pope Francis upon his arrival at Our Lady of Arabia Cathedral in Awali, south of the Bahraini capital Manama, on Nov. 4, 2022. (photo: Marco Bertorello / AFP via Getty Images)


In an ongoing dialogue with Ecumenical Patriarch Bartholomew of Constantinople, the successor of St. Andrew the Apostle and “first among equals” among the bishops of the Eastern Orthodox Church, Pope Francis has expressed his belief that Catholics and Orthodox will one day attain full communion. Eastern Orthodox — as opposed to Eastern-rite Catholics who differ from Latin-rite Catholics in custom and liturgical practices but accept the primacy of jurisdiction of the Bishop of Rome — gradually separated from Rome in the Middle Ages and are today composed of a variety of Orthodox churches, the largest of which is the Russian Orthodox Church with nearly 100 million members. Orthodox and Catholics both accept the first seven Ecumenical Councils of the Church as well as the seven sacraments and apostolic succession, but differ in key areas as well, most notably the primacy of the pope.

Another notable area of difference between them is the date of Easter. In 2024, Catholics and much of the rest of the world celebrate Easter on March 31, while the Orthodox celebrate Easter on May 5. The difference is due to the fact that most Orthodox churches use the Julian calendar introduced by Julius Caesar in 45 B.C. and the Catholic Church uses the Gregorian calendar introduced by Gregory XIII’s 1582 papal bull Inter Gravissimas (“Among the Greatest Concern”). Developing an accurate calendar can be a challenge, as a year or amount of time it takes the earth to make a complete revolution around the sun cannot be neatly organized into days and months. Such a revolution takes nearly a quarter of a day longer than 365 days, so calendars must be adjusted for this difference or be increasingly off year-to-year. Both the Julian and Gregorian calendars were efforts to account for the movements of the sun and the moon, with the Gregorian calendar being the more successful effort to do so.

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