"For although almost all churches throughout the world celebrate the mysteries on the Sabbath [7th day - Saturday] of every week, yet the Christians of Alexandria and at Rome, on account of some ancient tradition, have ceased to do this." (Socrates, Ecclesiastical History, b.5, ch.22, found in Nicene and Post-Nicene fathers)
But the seventh day is the sabbath of the LORD thy God:
Exodus 20:10
