Questionable prophet dependency impeding builds on Mac M1

Hi,

Prophet currently depends on LunarCalendar, which in turn depends on PyEphem (https://github.com/brandon-rhodes/pyephem).

PyEphem provides an ephem Python package for performing high-precision astronomy computations. The underlying numeric routines are coded in C (...).

Can you explain in one sentence why you need to depend on a high-precision astronomy library, written in C, in prophet ?

Can't you just use https://pypi.org/project/holidays/ ?

Thanks :)