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 history
of mathematics, chronology, and early Christianity, ultimately resulting in his
lucid webpage “Christian Era and Universal Time”, he became fascinated by the
Alexandrian computus, i.e. the Alexandrian way of
practising the computus paschalis
being the science developed from the early third century for the purpose of
determining (Alexandrian or Julian) calendar dates of Paschal Sunday.
In 2009 he succeeded, by using NASA’s
Six Millennium Catalog of Phases of the Moon, in
determining the original Metonic 19‑year lunar
cycle underlying the fifth century Latin text De ratione paschali
containing the legendary 19‑year Paschal cycle of the famous third
century Alexandrian computist Anatolius.
His reconstruction of this lost 19‑year lunar cycle, referred to as the
proto‑Alexandrian 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 pioneering 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. After having
argued, at a similar conference in 2018, that shortly before the council of Nicaea in AD 325, turning point in the history of
Christianity, in Alexandria a completely different Metonic
19‑year lunar cycle, referred to as the archetypal Alexandrian cycle,
must have been constructed, he decided to write a book describing how he, again
using NASA’s Six Millennium Catalog, reconstructed
this very 19‑year lunar cycle as well as Anatolius’
19‑year lunar cycle, the latter apparently being equal to the proto‑Alexandrian
cycle. The first edition of this book, entitled “Reconstructing Metonic 19‑year Lunar Cycles (on the basis of NASA’s
Six Millennium Catalog of Phases of the Moon)”,
appeared in 2019; in this groundbreaking book he not only reconstructs both
these historically important lost ante‑Nicene Alexandrian Metonic 19‑year lunar cycles and explains the
(unmistakably ante‑Nicene) 2‑day gap between them but also
describes the development from the archetypal Alexandrian cycle to the so
called classical Alexandrian cycle from which around the great calendar reform
in AD 1582, turning point in the history of chronology, a more realistic
(but necessarily also more complicated) method for determining Gregorian
calendar dates of Easter would be developed.
© Jan Zuidhoek 2019‑2022