On the 21st: Among other sources, the Daily Mail hails it as the Star of Bethlehem:
Both gas giants, they have been gradually getting closer to one another since the start of summer.
And, on December 21, the planets will appear to virtually overlap in the sky in a phenomenon not seen since the Middle Ages.Jemma Carr, “Return of the star that guided three wise men to Bethlehem?” at Daily Mail
Note: There are about as many theories about the Star of Bethlehem as about the origin of life. Here are some.