"Perhaps the boldest thing,
the most revolutionary change the Church ever did,
happened in the first century.
The holy day,
the Sabbath,
was changed from Saturday to Sunday.
"The Day of the Lord" (dies Dominica) was chosen,
not from any directions noted in the Scriptures,
but from the Church's sense of its own power.
The day of resurrection,
the day of Pentecost,
fifty days later,
came on the first day of the week.
So this would be the new Sabbath.
People who think that the Scriptures should be the sole authority,
should logically become 7th Day Adventists,
and keep Saturday holy."
Sentinel, Pastor's page, Saint Catherine Catholic Church, Algonac, Michigan, May 21, 1995 
Remember the sabbath day, to keep it holy.
But the seventh day is the sabbath of the LORD thy God:
Exodus 20:8,10