Right, I know he existed. But what is he doing in this article? I'm loath to cry "LLM!" but this seems like a really weird error for a human to make. Sort of like getting Babe Ruth, Ruth Bader Ginsberg and the Lindbergh Baby confused in your head.

Could just be sloppy writing. The first instance that grabbed me was "The Julian Date simply counts the number of days from an arbitrary remote reference point", it's not arbitrary, it was chosen specifically because three major time cycles, solar, lunar, and the other one, all coincide at that point.