This is a question from a reader of “Christian History” (part of Christianity Today magazine):
“When did the Christian church switch the Sabbath from Saturday to Sunday?
No specific names or dates are associated with the church’s shift from observing the holy day on Saturday to observing it on Sunday. At first, especially when many Christians were converted Jews, their holy day was Saturday. However, because the Resurrection and the beginning of Creation had both occurred on the first day of the week (Sunday), the church soon observed that day instead. (More Gentiles were becoming Christians as well, which contributed to a desire to shake off Jewish customs.) By the end of the first century, Sunday worship was the norm…
It’s important to note that the Sabbath was not simply moved; Christians altered the observance as well as the day. Hallmarks of the early Christian “Lord’s day” celebration, according to Justin Martyr (ca. 100-ca. 165), included readings from Scripture (particularly the Gospels), a sermon, communal prayer, and Communion—very different from Jewish Sabbath observance. By Jewish standards, Christians don’t keep the Sabbath at all…”
Christianity Today International/Christian History magazine, 2001