This website details a proposal for a New Coptic Calendar, covering the motivation, guiding principles, methodology, and sample results of the proposal.

Additionally, it links to the Python computer program used to perform the calculation, and the resulting database of dates for 500 years. 

Summary of Proposal

  • One time change: A one-time adjustment to realign 1 Thout, the start of the Coptic year, to its original corresponding date of 29 August in the Gregorian calendar.

  • Leap years: A change to the method for computing leap years to prevent drift between the New Coptic Calendar and the Gregorian Calendar, and maintain their alignment in perpetuity.

  • Fixed feasts: No changes to the dates of the fixed feasts and observances in the liturgical calendar of the Coptic Orthodox Church. For example, the Feast of the Nativity remains on 29 Kiahk. Only its corresponding date in the Gregorian Calendar changes to 25 December.

  • Easter: A new unified Computus — the calculation of the Feast of the Resurrection — for all of Christendom. It abides by the rule for calculating Easter established by the Council of Nicaea, but forgoes ancient estimations for the Vernal Equinox and the Paschal Full Moon in favor of precise astronomical modeling, as would be observed from the Great City of Our God Jerusalem.

This proposal has been prepared by servants of St. Basil American Coptic Orthodox Church in San Diego, California, USA. 

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