"Kalender-Formeln" von Rektor Chr. Zeller in Markgröningen, Mathematisch-naturwissenschaftliche Mitteilungen des mathematisch-naturwissenschaftlichen Vereins in Württemberg, ser. 1, 1 (1885), pp.54-58 - in German.
Note the Continental use of comma for decimal separator and dot for multiplication.
From scans by Anthony Holley, of photocopies.
The paper shown above is translated and discussed in zel-1885.htm.