This is an online version of the star calendar that can be found on the so-called "Kastensarg des Nacht" which is currently on display in the Roemer- und Pelizaeus Museum in Hildesheim. The calendar is missing a few weeks and two entire months — for reasons that are unknown to me at present — and these will therefore not be reconstructed; the goal is to have the most accurate digital version of this calendar possible. Clicking the names of the individual months of a season will open a new page which contains a table displaying the three different weeks of said month.
I would also like to thank the folks over at the McMaster University for providing a great list of decan stars which helped me greatly in identifying glyphs that I found difficult to decipher.
There are, however, a few differences between my decans and theirs; if you wish to know more about said differences and the overall difficulties I encountered whilst trying to digitise this star calendar, please take a look at Unforseen difficulties
If you wish to find out more about decan stars in general (also known as Baktiu) then you can click the link here.