I might need to calculate the position/phase of various astrological items for my TDE troupe in the year 1013 Bosparans Fall... and while I know some of their cycle timesDSA2 - Enzyclopaedia Aventurica p55 and at least the calculations for Mada are given in the eternal calender perfectly \$(\text{Day}+30*(\text{Month}-1)+\text{Year}_\text{Hal}\mod{28} = 0(\text{New}))\$. Yet I lack starting points for some of the other planets and constellations.
However, I remember that there was a tool to calculate the astrological data for any given day at some point: Is there a publisched point or constellation from which one can calculate forward/backwards and where is it noted?