Looks like it’s not a case of a fork and but rather of different publishers all trying to serve a common need with a well understood formula. There used to be many almanacs, then there were two, now there is one.
In Italy, where I grew up, my grandparents used to read the Almanacco di Barbanera; the first edition came out in 1762. It is still around https://www.barbanera.it/
barbanera = black beard
Similarly in the Netherlands, my grandparents used to have the Enkhuizer Almanak. Also still around after 430 years https://www.almanak.nl/