Coptic calendar

Structure and characteristics

The year has twelve months of 30 days and an additional short month of five days (six in leap years), often referred to as the epagomenal or intercalary days. Months retain ancient names such as Thout, Paopi and Koiak. Leap years follow the Julian system with one extra day every four years, which means the calendar gradually diverges from the Gregorian civil calendar used internationally.

Months (selection)

• Thout
• Paopi
• Hathor
• Koiak
• Tobi
• Meshir
• Paremhat
• Parmouti
• Pashons
• Paoni
• Epip
• Mesori
• Nasie (intercalary)

History and origin

The calendar descends from the ancient Egyptian civil calendar and was adapted in late antiquity for Christian liturgical use. Its era, commonly used in church documents, begins with the year of the martyrs (Anno Martyrum), which dates from the late third century AD. The system blends Egypt's long-standing agricultural seasons with reforms that parallel the Julian calendar's leap rule.

Uses and importance

The Coptic calendar remains central to the life of the Coptic Orthodox community (Coptic Church) for fixing feast days, fasts and the liturgical cycle. It is also used in rural and agricultural contexts in Egypt where planting and harvest rhythms historically aligned with its seasonal structure. For modern civil purposes, most Egyptians use the Gregorian calendar, but the Coptic calendar continues to mark religious identity and seasonal customs.

Notable distinctions and conversions

Because its leap rule mirrors the Julian calendar, the Coptic calendar is currently offset from the Gregorian calendar by a number of days that changes slowly over centuries. The Coptic new year usually falls on 11 September of the Gregorian calendar (or 12 September in Gregorian leap years). For further technical details and historical comparisons, see summaries of the underlying ancient Egyptian calendar.