Jan Zuidhoek (email@example.com) was born in the year 1938, studied mathematics with physics and astronomy at the university of Utrecht from 1960 to 1969, and was a teacher of mathematics from 1970 to 2001 at Gymnasium Celeanum in Zwolle. He is the author of the sextilingual website millennium (www.janzuidhoek.net), on which some subjects are treated which are tied up with questions which we may encounter in the field of chronology, namely our era in its capacity of linear system of numbered calendar years, the millennium question, the Julian, the Alexandrian, and the Jewish calendar in antiquity, Roman and Alexandrian Paschal full moons and Paschal cycles, Metonic structure, and the date of Jesus’ crucifixion. He was the first who determined all possible dates of Jesus’ crucifixion in a systematic way (see Anni Domini). He was also the first who put a modern complete reproduction of Dionysius Exiguus’ Paschal table, of the classical Roman Paschal cycle, and of Beda Venerabilis’ Paschal table on Internet.
In the framework of the third international conference on the history of the computus paschalis, held at the university of Galway in July 2010, he held a lecture entitled “The initial year of De ratione paschali and the relevance of its Paschal dates”. In the article concerned (with the same name) he shows how he (in the year 2009), with the help of the catalogue of phases of the moon of Fred Espenak (NASA), reconstructed the 19-year proto-Alexandrian cycle underlying the 19-year Paschal cycle of Anatolius and determined the initial year of this famous Paschal cycle; this article has recently appeared in print (see Brepols). A thoroughly revised version of this article is already ready for publication. Not only the proto-Alexandrian cycle, but also the classical Alexandrian cycle was reconstructed (in the year 2010) by him. The article he wrote about it, will be published within the foreseeable future, either in print or on Internet.
In April 2018, on the occasion of a reunion of former pupils, teachers, and former teachers of Gymnasium Celenium, he gave some lessons of mathematics on the numbers of elements of the infinite sets Z, Q, and R and the paradox of Russell (see Bertrand). At present he prepares a lecture (entitled “Reconstructing the Alexandrian 19-year lunar cycle”) he hopes to be able to hold on the occasion of the seventh international conference on the history of the computus paschalis to be held at the university of Galway in June 2018.