By Bernard Cohen.
Abstract: The location of Easter in the calendar has been a source of disagreement among the Christian Churches for over 2000 years. In this paper, we will explore the history of the calculation of the date of Easter, from its original coincidence with Passover in the Hebrew lunisolar calendar, through the political and sociological problems caused by differences among the methods used for calculating its date in the Roman solar calendar. This will take us a journey through four millennia of popes, bishops, monks, kings, queens, theologians, astronomers, mathematicians, computists, settlers and terrorists from Babylon, Jerusalem, Rome, Leptis Magna, Alexandria, Byzantium, Nicea, Ephesus, Smyrna, Athens, Scythia Minor, Canterbury, Whitby, Iona, the Holy Isle and Belfast. And we will also have to learn some astronomy and mathematics.
Keywords: Easter, Passover, lunar and solar calendars, computus.
Biographical Note: Bernard Cohen was born in Glasgow. Bernie is Emeritus Professor of Computing at City, University of London. He held the Racal Chair of IT at the University of Surrey from 1984 to 1990 and was a telecommunications systems engineer with ITT Inc. from 1965 to 1984. He graduated from Glasgow University in 1984 with a BSc in Natural Philosophy and a post-graduate diploma in Numerical Analysis and Computer Programming. He is a Chartered Engineer, a Fellow of the British Computer Society and a Member of the Institution of Engineering and Technology.