The Ember Weeks—the weeks in which the Ember Days occur—are the week between the third and fourth Sundays of Advent, between the first and second Sundays of Lent, the week between Pentecost and Trinity Sunday, and the week beginning on the Sunday after Holy Cross Day (September 14), the liturgical Third Week of September.
In pagan Rome offerings were made to various gods and goddesses of agriculture in the hope that the deities would provide a bountiful harvest (the feriae messis in July), a rich vintage (the feriae vindimiales in September), or a productive seeding (the feriae sementivae in December). At first the Church in Rome had fasts in June, September, and December. The Liber Pontificalis ascribes to Pope Callixtus I (217-222) a law regulating the fast, although Leo the Great (440-461) considers it an Apostolic institution. When the fourth season was added cannot be ascertained, but Pope Gelasius I (492-496) speaks of all four.
The earliest mention of four seasonal fasts is known from the writings of Philastrius, bishop of Brescia (died ca 387) (De haeres. 119). He also connects them with the great Christian festivals.
The Christian observation of this seasonal observance of the Ember days had its origin as an ecclesiastical ordinance in Rome and spread from there to the rest of the Western Church. They were known as the jejunium vernum, aestivum, autumnale and hiemale, so that to quote Pope Leo's words (A.D. 440 - 461) the law of abstinence might apply to every season of the year. In Leo's time, Wednesday, Friday and Saturday were already days of special observance. In order to tie them to the fasts preparatory to the three great festivals of Christmas, Easter and Pentecost, a fourth needed to be added "for the sake of symmetry" as the Encyclopaedia Britannica 1911 has it.
From Rome the Ember days gradually spread unevenly through the whole of Western Christendom. In Gaul they do not seem to have been generally recognized much before the 8th century.
Their observation in Britain, however, was embraced earlier than in Gaul or Spain, interestingly, and Christian sources connect the Ember Days observations with Augustine, AD. 597, said to be acting under the direct authority of Pope Gregory the Great. The precise dates appears to have varied considerably however, and in some cases, quite significantly, the Ember Weeks lost their connection with the Christian festivals altogether. Spain adopted them with the Roman rite in the eleventh century. Charles Borromeo introduced them into Milan in the sixteenth century.
In the Eastern Orthodox Church ember days have never been observed.
Other regulations prevailed in different countries, until the inconveniences arising from the want of uniformity led to the rule now observed being laid down under Pope Urban II as the law of the church, at the Council of Piacenza and the Council of Clermont, 1095.
These dates are given in the following mnemonic:
Or in the clumsy old English rhyme
The ember days, began on the Wednesday immediately following those days. This meant, for instance, that if September 14 were a Tuesday, the ember days would occur on September 15, 17, and 18. As a result the ember days in September could fall after either the second or third Sunday in September. This, however, was always the liturgical Third Week of September, since the First Sunday of September was the Sunday closest to September 1st (August 29 to September 4). As a simplification of the liturgical calendar, Pope John XXIII modified this so that the Third Sunday was the third Sunday actually within the calendar month. Thus if September 14 were a Sunday, September 24, 26 and 27 would be ember days, the latest dates possible; with September 14 as a Saturday, however, the ember days would occur on September 18, 20 and 21 - the earliest possible dates.
Prior to the reforms instituted by the Second Vatican Council, the Roman Catholic Church mandated fasting (only one full meal per day plus two partial, meatless meals) on all Ember Days (which meant both fasting and abstinence from meat on Ember Fridays), and the faithful were encouraged (though not required) to receive the sacrament of penance whenever possible. On February 17, 1966, Pope Paul VI's decree Paenitemini excluded the Ember Days as days of fast and abstinence for Roman Catholics.
The revision of the liturgical calendar in 1969 laid down the following rules for Ember Days and Rogation days:
They may appear in some calendars as "days of prayer for peace".
They were made optional by churches of the Anglican Communion in 1976.
The present rule which fixes the ordination of clergy in the Ember weeks was set in documents traditionally associated with Pope Gelasius I (492 - 496). In the earlier church ordinations took place whenever necessity required. Gelasius is stated to have been the first who limited them to these particular times. The rule once introduced commended itself to the mind of the church, and its observance spread. We find it laid down in the pontificate of Archbishop Ecgbert of York, A.D. 732 - 766, and referred to as a canonical rule in a capitulary of Charlemagne, and it was finally established as a law of the church in the pontificate of Pope Gregory VII, ca 1085.
However, others maintain that the term is derived from the Latin quatuor tempora, meaning "four times" (a year), while folk etymology even cites the phrase "may ye remember (the inevitability of death)" as the source. J. M. Neale's Essays of Liturgiology (1863), Chapter X, explains the etymology:
"Quattuor tempora" was rendered into Irish Gaelic quite literally as "Laethanta na gCeithre Thráth," meaning "the days of the four times" and into somewhat archaic English as "Quarter tense".