And the Church says that the Sabbath begins at sundown on the evening before, as the Jewish Sabbath does.
As St. Chuck has pointed out, look at the Vespers hour in the Divine Office. It begins celebrating the Sabbath on Saturday evening.
What's next? Is a mass invalid if a priest wears the stole on the outside of the chasuble versus under the chasuble?
You're straining at a gnat, scraping to find another reason to trash the post-Vatican II Church.
But never the Mass, except for those rare and exceptional dispensations for well-considered pastoral reasons. I will concede that much, but no more.