Sunday and the Sabbath

Christians from very early times have had differences of opinion on the question of whether the Sabbath should be observed on a Saturday or a Sunday. The issue does not arise for Jews, for whom the Shabbat is unquestionably on Saturday, nor for Muslims whose day of assembly (jumu'ah) is on a Friday.

The first evidence of a differentiation from the traditional Jewish Shabbat observance, and the religious observance of the first day of the week, appears in Acts 20:7 where the disciples met to participate in the ordinance of the sacrament. Col 2:16 also demonstrates that the early Christians were beginning to differ from their Jewish neighbors, not only in the new tradition of eating foods that had been prohibited under Judaism, but also in their observance of the Sabbath day. The Apostle John also refers to the "Lord's Day" in Rev 1:10 - indicating that those to whom he was writing were familiar with the term. Some early Jewish Christians observed the Sabbath on Saturday, but by the first half of the second century an increasing number of Christians would gather for worship on Sunday. Some continued to observe the Sabbath on Saturday, until even the crusader period. The practice was discouraged, but not suppressed. [citations?]

On 7 March 321, Constantine I decreed that Sunday (dies Solis) will be observed as the Roman day of rest [CJ3.12.2]:

On the venerable day of the Sun let the magistrates and people residing in cities rest, and let all workshops be closed. In the country however persons engaged in agriculture may freely and lawfully continue their pursuits because it often happens that another day is not suitable for grain-sowing or vine planting; lest by neglecting the proper moment for such operations the bounty of heaven should be lost. [7]
Though some Christians use the decree in support of the move of the Sabbath day to Sunday, in fact the decree was in support of the worship of the Sun-God (see Sol Invictus). In any event, the decree did not apply to Christians or Jews. It was part of the Roman civil law and religion and not an edict of the Church.

Many Christians today consider Sunday to be the Sabbath day, a holy day and a day of rest and church-attendance. Denominations which observe Saturday as the Sabbath are called Sabbatarians; however, the name Sabbatarian has also been claimed by Christians, especially Protestants, who believe Sunday must be observed with just the sort of rigorous abstinence from work associated with the Jewish Sabbath (exemplified by Eric Liddell as depicted in the film Chariots of Fire). For most Christians the custom and obligation of Sunday rest has not been as strict.

In Orthodox Christian families and communities, some activities are not done, e.g. working, doing something that requires somebody else to work such as buying goods or services (including the use of public transport), driving a car, gardening, washing a car, etc.[verification needed] Exceptions which are allowed are making use of religious services, and, usually, using electricity, and urgent medical matters. In Roman Catholicism, those who work in the medical field, in law enforcement, or soldiers in a war zone are dispensed from the usual obligation to avoid work on Sunday.

The majority of Christians have continued to observe the Sabbath on Sunday ever since, although throughout history one sometimes finds Christian groups that continued or revived the observance of the Saturday Sabbath. More recently in history, Christians in the Seventh-day Adventist, Seventh Day Baptist, and Church of God (Seventh-Day) denominations (along with many related or similar denominations), as well as many Messianic Jews, have revived the practice of abstaining from work and gathering for worship on Saturdays.

Many languages lack separate words for "Saturday" and "Sabbath". Eastern Orthodox churches, as well as many Roman Catholics, distinguish between the Sabbath (Saturday) and Sunday, which some Christians traditionally call the Lord's Day (Rev. 1:10). However, many Protestants and Roman Catholics do refer to Sunday as the Sabbath, though this is by no means a universal practice among Protestants and Catholics. Quakers traditionally refer to Sunday as "First Day" eschewing the pagan origin of the English name.

In Roman Catholicism liturgy, Sunday begins on Saturday evening. The evening Mass on Saturday is liturgically a full Sunday Mass and fulfils the obligation of Sunday Mass attendance, and Vespers (evening prayer) on Saturday night is liturgically 'first Vespers' of the Sunday. The same evening anticipation applies to other major solemnities and feasts, and is an echo of the Jewish practice of starting the new day at sunset (so that Sabbath starts on the Friday night).

In the Eastern Orthodox Church, Sunday begins at the Little Entrance of Vespers (or All-Night Vigil) on Saturday evening and runs until "Vouchsafe, O Lord" (after the prokeimenon) of Vespers on Sunday night. During this time, the dismissal at all services begin with the words, "May Christ our True God, who rose from the dead…". Anyone who wishes to receive Holy Communion at Divine Liturgy on Sunday morning is required to attend Vespers the night before (see Eucharistic discipline). Among Orthodox Christians, Sunday is considered to be a "Little Pascha" (Easter), and because of the Paschal joy, the making of prostrations is forbidden, except in certain circumstances. The Russian word for Sunday is Voskresenie, meaning "Resurrection day". In Greek the word for Sunday is Kyriake (the "Lord's Day").

The Polish word for Sunday (niedziela) can be translated as "without acts (work)"