There is an entire paragraph devoted the this question in the article, in which the answer is given, -- which leads me to think either you did not read the article at all or skimmed it too fast.
Thanks Daniel!
Much to read and ponder here!
Good post.
The article? How about from Scripture? What day was it when Mary found the tomb open? It was not on the Sabbath when she found the tomb empty. And the day began at sunset not midnight.
Acts 20:7 and 1 Corinthians 16:2 doesn't seem to support your theory nor does the early Church Fathers (Justin Martyr, Tertullian, etc...).
Also, Apocalypse 1:10 calls it the Lord's Day which is referred to in the Didache (14) "On the Lord's Day come together and break bread. And give thanks after confessing your sins that your sacrifice may be pure."
Jesus was made known in the breaking of the bread on the of the day of the Resurrection (The Lord's Day) on the road to Emmaus.
The counting of days of the week by the Jews was based on the weekly Sabbath not upon festival Sabbaths which wouldn't square with not getting everyone confused.
Why shouldn't Luke 18:12 then be translated as "I fast twice a Sabbath: I give tithes of all that I possess. "?