How does the Church decide, for example, when next year's Lent will start?

By CopticBot.ai (Coptic Space Inc.) · Last reviewed 2026-10-10

The calculation of the date of the Great Lent and the Feast of the Resurrection (Pascha) in the Coptic Orthodox Church is based on the Epact Calculation (known in Arabic as Hissab el-Abaqti). This system was established by St. Demetrius the Vineyard-Dresser, the 12th Pope of Alexandria, in the late 2nd century.

Before this calculation was formalized, the early Church struggled with when to celebrate the Resurrection. The Council of Nicaea (325 AD) eventually adopted the Alexandrian method, entrusting the Pope of Alexandria with the responsibility of determining the date each year and announcing it to all other churches.

The determination of the Great Lent is directly tied to the date of the Resurrection. To find the start of Lent, the Church uses the following criteria:

1. The Astronomical Rules

The date of the Resurrection must fulfill three specific conditions:

• It must be after the Vernal Equinox (March 21).
• It must be after the full moon that follows the Vernal Equinox (the first Jewish Passover moon).
• It must be on the Sunday following that full moon.

The Coptic Church remains strictly faithful to the decrees of the Council of Nicaea, ensuring that we never celebrate the Resurrection before or during the Jewish Passover, as the type (Passover) must be fulfilled before the reality (the Resurrection of Christ).

2. Working Backward from Pascha

Once the date of the Resurrection is determined via the Epact system, the start of the Great Lent is calculated by counting backward:

• The Great Lent: It lasts for 55 days. This includes the 40 days of Christ’s fast, the one week of Preparation (Pre-Lent), and the eight days of Holy Week (including Lazarus Saturday and Palm Sunday).
• Jonah's Fast: This occurs exactly two weeks before the start of the Great Lent.

3. The Role of the Coptic Calendar

The Church uses the ancient Egyptian calendar, which consists of 13 months (12 months of 30 days and the short month of Nasie). Specifically, the start of the Fast of the Great Lent is often announced in relation to the Coptic months (e.g., in the month of Amshir or Baramhat).

Summary of the Process

1. Identify the Vernal Equinox (March 21).
2. Locate the next Full Moon (the Epact Moon).
3. The following Sunday is Easter Sunday (according to the Julian/Coptic calendar).
4. Count back 55 days to find the Monday that begins the Great Lent.

By following this rigid astronomical and ecclesiastical system, the Church maintains the spiritual harmony of the liturgical cycles, ensuring that the fast leading up to the "Feast of Feasts" is spiritually and historically aligned with the life of Christ.