The Greek Orthodox Church began the pre-Lenten period, known as Clean Monday, on February 23rd, marking the start of a more rigorous fasting season than observed in Western Christian traditions. This year, Clean Monday falls five weeks before Easter, a divergence that highlights the differing calculations used to determine the date of the holiday and the subsequent fasting periods.
While Western churches follow the Gregorian calendar, established with reforms in the 16th century, Orthodox churches adhere to the Julian calendar for determining Easter. This difference in calendrical systems can result in Easter falling up to five weeks apart, though occasionally the dates coincide, as they will in 2025. The pre-Lenten fast in the Orthodox Church is always two days longer than in the Catholic Church, beginning not with Ash Wednesday, but with Clean Monday.
The period leading up to the Great Fast, as the Lenten season is known in the Orthodox tradition, is itself structured with distinct phases. The week preceding Clean Monday is known as Maslenitsa, or Cheese Week, a time when meat is abstained from, but dairy products and eggs are still consumed. This represents followed by Forgiveness Sunday, a day dedicated to seeking reconciliation and forgiveness from others before the more austere fasting period begins.
Even before Clean Monday, a preparatory period commenced on February 1st, with the use of the Triodion in liturgical services. The Triodion is a liturgical book containing hymns and readings specifically designed to prepare the faithful for the spiritual discipline of Lent. According to a statement from Greek Orthodox Metropolitan Arsenios Kardamakis, this period is a call for introspection and repentance, urging believers to “guard the heart from wrath and division and cultivate love, gratitude and humility.”
Clean Monday and Good Friday are considered the most important fasting days of the year for Orthodox Christians. During the Great Fast, all animal products – including meat, dairy, eggs, and fish – are prohibited. On Clean Monday and Good Friday, complete abstinence from food is observed by many faithful. Beyond the Great Fast, the Orthodox Church observes other significant fasting periods before Christmas, the Feast of Saints Peter and Paul, and the Dormition of the Theotokos (Assumption of Mary). Wednesdays and Fridays are also traditionally observed as fast days, commemorating the betrayal of Jesus and his crucifixion, respectively.
The differing dates for Easter and the associated fasting periods stem from historical divisions in the calculation of the holiday, originating with the return of Jews from the Babylonian exile and their method of determining the date of Passover based on the first full moon after the spring equinox. The Council of Nicaea in 325 AD attempted to standardize the calculation, but the adoption of the Julian and later Gregorian calendars led to ongoing discrepancies. Discussions regarding a unified date for Easter have been ongoing for decades, but no resolution has been reached, as some churches continue to adhere to the older Julian calendar.
