The Coptic Calendar is a solar calendar used by the Coptic Orthodox Church and other Christian communities in Egypt. It consists of 13 months: 12 months of 30 days each and an additional month, called Nasi, which has 5 days in a common year and 6 days in a leap year. The calendar begins on the 29th of August in the Gregorian calendar, aligning with the Coptic New Year. This calendar is based on the ancient Egyptian calendar and is primarily used to determine the dates of religious festivals and events. The Coptic Calendar is significant for tracking the liturgical year, including important celebrations like Christmas and Easter, which are observed on different dates than in the Gregorian system.