Christian Zeller


Julius Christian Johannes Zeller was a German mathematician.
Originally trained in mathematics, geography and theology, in 1874 Zeller became Director of the Seminary in Markgröningen and a girls' orphanage. In 1882 he became a member of the Société Mathématique de France. The following year, on 16 March 1883, he delivered a short account of his congruence relation, which was published in the society's journal.
He was later awarded the Order of Friedrich, First Class, and the Ritterkreuz of Württemberg. He retired in 1898, and died in the following summer.

Works

On calendrical calculations

Each of these four similar papers deals firstly with the day of the week and secondly with the date of Easter Sunday, for the Julian and Gregorian Calendars.
He also produced a reference card, .

On number theory

See number theory.