New Julian Date reference, from an online site:
    https://researchgate.net/publication/316558298

Author: Peter Baum, Aesir Research

Article: Date Algorithms
         Version: 5
         Last modified: October 21, 2020

The article Provides lots of test data as well as the best 
description of Julian Date versus calendars I've found.  
The test data in Table 2 have been checked against the NASA 
JPL Time Conversion Tool and the Gregorian data are tested 
here against Raku. 


