The calendar is always a good topic, If you Look up “365 Days of Astronomy” from last fall I did a podcast with my Rabbi on the Jewish calendar, and on last march 15 on the Julian Calendar which was the predecessor to the modern civil calendar.
On a silly note my favorite one was always “How to build a Mikva on Mars”. would take some actual research.
As for the day of the week in space it is my understanding the Ilan Ramon asked about this and was told to keep Florida or Houston time (I forgot which). Of course that only works when you are in Earth orbit, if you were to say travel to Mars things get a lot more complex.