Peter and Paul (Apostle) post office used to be called Pentecost . About the church establishment of this post referred to in the regulations of the apostolic "After Pentecost celebrate a Week, and then fast, justice requires and rejoice upon receiving the gifts of God, and to fast after the ease of the flesh."
Lent begins on Monday, exactly one week after the of the Day of the Holy Spirit, following the Trinity. In other words, on the 57th day after Easter. Peter's post was established in memory Apostles Peter and Paul, who were fasting, preparing himself for preaching the Gospel.
Petrova duration of fasting depends on the day of Easter: the longest post can last for six weeks, and the shortest — eight days.
Petrov post always ends in Day of the Apostles Peter and Paul on July 12, unless the feast of Saints Peter and Paul will not be on Wednesday and not Friday.
Kitchen Apostles' Fast is lax — eliminate from the diet of foods of animal origin may be used in food only plant foods and fish. And, on Wednesday and Friday, it is not recommended to consume fish and vegetable oil, the other days are allowed to fish.