As a spin-off from the Rudolphine Tables and the related Ephemerides, Kepler published astrological calendars, which were very popular and helped offset the costs of producing his other work—especially when support from the Imperial treasury was withheld.
Som en afstikker fra de rudolfinske tavler og de relaterede efemerider udgav Kepler astrologiske kalendere, som var meget populære, og som hjalp til at producere hans andre værker — specielt når støtten fra det kejserlige skatkammer blev tilbageholdt.