I was…watching EWTN… and one of the priests there did mention that Sunday was the preferred day of worship because it corresponds with the day of Jesus’ resurrection which was celebrated in the early Church.
He said the Saturday Mass was instituted because so many Catholics (in modern society) were being forced to work on Sunday.
He made it seem as if, the Mass on Saturday was for Sunday workers.
I can see his point.
I have to wonder at times if I’m being disrespectful of Sunday worship because Saturday Mass is an easy go for me. I’m winding down my day; I’m geared toward the Mass; there are less young children at that Mass and to be honest it clears all day Sunday out for rest, reading and a family meal.
All that being said, by Jewish observance, sundown on Friday began the Saturday Sabbath. In the same way, Saturday sundown begins the Sunday worship for us.