Among many Christian Orthodox holidays, those in which fasting is determined by the church charter are especially distinguished. There are not many such dates in the calendar, but they occupy an important place in the liturgical life of the Church.
The church liturgical charter defines two holidays on which an Orthodox person must fast. At the same time, it is prescribed that fasting is strict - not only food of animal origin, but also fish is prohibited from eating. Both of these celebrations fall in September and are celebrated annually at a specific time.
On September 11, the Orthodox Church honors the Baptist of the Lord and the Prophet John. This day is named in the church calendar as the Beheading of John the Baptist. The Gospel story tells how the head of the great prophet was cut off at the behest of King Herod. Herod, however, was motivated to such dishonor by Herodias and her mother Salome. The Orthodox Church, remembering such a terrible murder of a righteous man, blesses a person with bodily and mental abstinence on this day.
Another Orthodox holiday during which fasting is laid is the day of the Exaltation of the Holy Cross, celebrated by the Church on September 27th. In addition to the Church's recollection of the historical event of the acquisition of the Life-giving Cross and its erection with a huge gathering of the people of Constantinople, this holiday testifies to the price at which salvation was granted to mankind. The Church determines fasting for the Exaltation as a sign of remembrance of the atoning sacrifice of Jesus Christ. The believer tries on this day to raise his thoughts to the realization of the death of the Savior on the cross and the love of God, thanks to which the Lord did not spare the beloved Son for the sake of saving people and giving a person the opportunity to be in paradise after death.
In addition to these holidays, it is worth mentioning a few more dates. So, there is always a fast on the feast of the Lord's Entry into Jerusalem (Palm Sunday). This is due to the fact that the celebration falls out on the penultimate Sunday before Easter, when Great Lent continues. It is worth noting that fasting is also defined on some great twelve holidays if the celebrations fall on a multi-day period of abstinence, as well as Wednesday or Friday (for example, the feast of the Annunciation of the Virgin, the Presentation of the Lord, the Entry of the Mother of God into the Temple, the Dormition of the Virgin, the Transfiguration of the Lord).
If a Great holiday falls on Wednesday or Friday (for example, the Protection of the Virgin, the memory of the holy apostles Peter and Paul, the Nativity of John the Baptist), then the fast is not canceled, but the use of seafood and fish is allowed on these days.