For the Orthodox Christian the Lord’s Day is the first day of the week. Often it is also called the eighth day in honor Our Lord’s Resurrection and the new life he brought. In the English language, and other languages of Germanic origin, the day is called Sunday or some linguistic variation. In many languages around the Mediterranean Sea the name for this day is derived from Lord’s Day, while other languages including Slavic languages use a word derived from the word Resurrection.
In the Judeo-Christian Scriptures, in Genesis, the seven day week is defined after the description of God’s efforts in establishing the world, and universe with the seventh day being the Sabbath, commemorating God’s day of rest. In Apostolic times the practice is noted in Acts of meeting together on the first day of the week for Eucharistic Sacrifice which is called the Lord’s Day in remembrance of Our Lord’s Resurrection. By the second century the Lord’s Day was looked upon as the day of rest and the day for celebrating the Divine Liturgy, replacing the Jewish Sabbath. Then in 325, the Council of Nicea formally declared that the Lord’s Day, Sunday, was the day of worship for Orthodox Christians.
Naming of the days of the week began when the Romans adopted the seven day week from Egypt during the early centuries of the Christian era using names from the then known planets. When the Germanic peoples adopted the seven day week from the Romans, they applied the names of the Teutonic deities to the days of the week. These Roman and Teutonic names have continued to be used today except that in some languages the first day has been renamed for the Lord’s Day or the Resurrection while the seventh day may be called the Sabbath.
In a large part of the world, the civil calendars have been altered making Monday the first day of the week thus placing Sunday as the seventh day.
The practice of observing the Divine Liturgy on the first day of the week has its origin in Apostolic times. From Apostolic times the first day of the week was a day of special observance for the Christian community as it assembled to celebrate the breaking of the bread as indicated in Acts 10.7 and 1 Cor, 16, 2. Later, the Didache of the second century gives the injunction “On the Lord’s Day come together and break bread. And give thanks, after confessing your sins that your sacrifice may be pure