[LogicWolfe]

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.

[ninalanyon]

On the other side of the pond there are more: https://en.wikipedia.org/wiki/Old_Moore%27s_Almanack in England published since 1697 and a similarly named one (without the k) in Ireland, https://en.wikipedia.org/wiki/Old_Moore%27s_Almanac since 1764

[mastazi]

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/