At the end of the 2nd century, the churches of Egypt and North Africa began to call the annual celebration of the resurrection of the saints “the Lord’s Day,” but it did not become a weekly celebration until the 4th century.
It seems that the annual celebration of “the Lord’s Day” began after the Quartodeciman controversy. In A.D. 193, the bishop of Rome wrote letters of excommunication to the churches of Asia because they did not accept his doctrine of Easter Sunday. In this debate, Bishop Polycrates said that he could only remember the Passover on the 14th of the month, according to the Old Testament instruction: “We observe the exact day, neither adding nor taking away. For in Asia also great lights have fallen asleep, which shall rise again on the day of the Lord’s coming.”1Eusebius, Church History, Book 5:24
The churches of Asia did not actually celebrate the resurrection: they remembered the Passover. But perhaps in response to the Quartodeciman debate, the churches of Egypt and North Africa began to celebrate the resurrection of the saints, who will rise on the Lord’s Day. They called this annual celebration “The Lord’s Day.” Tertullian described it as the anniversary of the birthdays of those who will resurrect: “As often as the anniversary comes around, we make offerings for the dead as birthday honors.”2De Corona, Chapter 3 In Egypt and North Africa, the expression “the Lord’s Day” was used only in the context of the Easter celebration. Origen listed the days of the resurrection season as the Lord’s Day, the Preparation, the Passover, and the Pentecost.3Origen, Contra Celsum, Book VIII, Chapter 22 Both Origen and Tertullian compared the significance of the Lord’s Day to that of the Day of Pentecost.4On Idolatry, Chapter 4
By the 4th century, the churches throughout the world were calling the annual celebration of the resurrection “The Lord’s Day.”
In A.D. 324, one year before Rome called every Sunday “the Lord’s Day,” Eusebius, the bishop to the emperor, described “the Lord’s Day” as the time to celebrate “rites like ours in commemoration of the Savior’s resurrection.”5Eusebius, Church History, Book 3.27 Of course, these were not rites that were performed on a weekly basis.