Wednesday and Friday Fasting
In brief
Besides the four fasting seasons, the Orthodox Church keeps two fast days nearly every week of the year: Wednesday, which recalls Christ's betrayal by Judas, and Friday, which recalls His Crucifixion. On these days the faithful abstain from the same foods as in the longer fasts. The practice is one of the oldest in Christianity, attested already in the first or second century, and it turns the ordinary week into a small weekly Pascha and a weekly Cross.
What the two days commemorate
The weekly fast is not arbitrary; each day carries a memory. Wednesday marks the day the Church remembers the betrayal — when Judas went to the chief priests and "they covenanted with him for thirty pieces of silver" (Matthew 26:15), setting the Passion in motion. Friday marks the Crucifixion itself, the day the Lord died on the Cross. So twice a week the Christian keeps step with the events of Holy Week: mourning the betrayal, and glorying "in the cross of our Lord Jesus Christ" (Galatians 6:14). It is the same logic by which the Church makes every Sunday a little Pascha; Wednesday and Friday are its answering days of sober love.
This rhythm is strikingly old. The Didache, a Christian manual usually dated to the first or early second century, already assumes it, and even sets it deliberately apart from the fasting days of others, who fasted on Mondays and Thursdays. The instruction is blunt about doing something distinctively Christian on distinctively Christian days — the memory of the Cross, not the calendar of anyone else, was to govern the Christian week. By the fourth century the Wednesday-and-Friday fast was simply assumed across the Church, East and West, and in the East it has been kept without interruption ever since.
How the days are kept
On Wednesdays and Fridays the traditional rule is the same abstinence used in the seasons: no meat, eggs, dairy, fish, wine, or oil, with the fine points spelled out under the fasting rules. In much common practice wine and oil — and sometimes fish — are allowed when a feast falls on one of these days, which is why the rule is read from a church calendar rather than from memory. The fast runs through the whole year with a few exceptions: it is set aside entirely during the fast-free weeks after Pascha, Pentecost, the Nativity, and Theophany, when the joy of the feast overrides the weekly discipline.
As with all Orthodox fasting, this is a discipline and not a law of sin: it is kept cheerfully, broken without scruple for illness, pregnancy, hospitality, or genuine need, and grown into gradually under a priest's guidance (economia). Beginners are often counseled to start with Fridays alone, or with a simple abstention from meat, and to add the rest over time.
The point of a small, steady fast
Kept faithfully, the two days do quietly what the great fasts do intensely. They keep the Cross in view when nothing on the calendar would otherwise raise it; they train the will in small, repeatable ways that the seasons then build upon; and they knit the solitary Christian into the practice of the whole Church, who fasts on the same days. The Lord said that when "the bridegroom shall be taken away from them," then "shall they fast in those days" (Mark 2:20) — and on Wednesday and Friday the Church takes Him at His word. For the larger question of why the Church fasts at all, see Why Orthodox Christians Fast.