**Concise Curriculum Vitae**

** ****Jan Zuidhoek was born in 1938, studied mathematics, physics,
and astronomy at the university of Utrecht from 1960 to 1969, and was a teacher
of mathematics from 1970 to 2001 at the Gymnasium Celeanum in Zwolle. After
having gone deeply into the fields of history of mathematics, chronology, and
history of early Christianity, he became fascinated by the Alexandrian computus,
i.e. the Alexandrian form of the computus paschalis being the science developed
from the beginning of the third century on behalf of the determination of the
date of Paschal Sunday. In 2009 he succeeded, by using NASA’s Six Millennium
Catalog of Phases of the Moon, in determining the initial year (AD 271) of De ratione paschali, i.e. the medieval
Latin text containing the legendary 19-year Paschal cycle of Anatolius, the
famous third century Alexandrian computist who invented the very first Metonic
19‑year lunar cycle. The underlying reconstruction of the so called
proto-Alexandrian 19‑year lunar cycle was the subject of the presentation
he gave at the international conference on the science of computus which took
place at the university of Galway in 2010. This presentation resulted in his
article entitled “The initial year of De
ratione paschali and the relevance of its paschal dates”, which was
published in 2017 in the proceedings of that conference. The presentation he
gave at a similar conference in 2018 led to this book, in which he describes
not only his reconstruction of both lost Alexandrian Metonic 19-year lunar
cycles actively constructed already before the first council of Nicaea (AD
325), turning point in the history of Christianity, but also the development
from the second of them to the particular Metonic 19-year lunar cycle from
which thirteen centuries later the Italian astronomer Luigi Lilio and
subsequently the German mathematician Christoph Clavius would develop a modern,
astronomically more correct, system for determining the Gregorian calendar date
of Easter Sunday.**

**some more photographs (thanks to Nico
Assies, Dick Hollemans, Sander Zuidhoek, Michiel van Sleen, again Sander
Zuidhoek, and Thom Snijders respectively)**

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**about 1995 Leuvenum
2005 (with Marie)**

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** Bunnik
2004 (with Marie and Siem)**

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** Hilversum
2007 (with Fiene)**

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** Putten
2006 (with Marie, Katja, and Fiene)**

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** Galway
2018 (with Immo Warntjes and Daniel P. Mc Carthy)**

**© Jan
Zuidhoek 2019-2021**