The Mathematical Basis of the Calendar Used by the Ethiopian Orthodox Twahedo Church for Fasting Periods and Religious Holidays

Abstract

The Ethiopian Orthodox Twahedo Church (EOTC) has been the most dominant religion fully supported by the government for many years. EOTC has its own calendar, which is genuinely respected by the people. Nowadays, the Ethiopian people officially celebrate five major religious holidays every year: the New Year called ‘Inqutatash’, Holy Cross, Christmas, Epiphany and Easter. Easter has no fixed date. The dates of some of the fasting periods and the religious holidays also vary from year to year. In this paper, number theory is applied to the determination of the calendar for the fasting periods and major holidays of the EOTC whose dates vary from year to year.