On Monday, one of the two fasts traditionally observed in summer began. Since it ends on the feast of the apostles Peter and Paul, it is called either the Apostolic or Peter's Fast.
This fast always begins a week after the celebration of the Orthodox Trinity or Pentecost. It always starts on a Monday.
Since Trinity is celebrated 50 days after Easter, it, and thus the beginning of this fast, has a floating date. There are years when the fast lasts for 42 days, and there are years when it lasts only 8 days. This year it will last until July 11.
The proper name of this fast is quite long and complex — the Holy Fast of the Holy Glorious and All-Praised Apostles. Its traditional name is associated with the apostles — the apostolic or Peter's Fast. This lengthy summer fast has been known since ancient times. Previously, it was observed by those who, for some reason, did not keep the Great Fast. But later, the custom arose to observe the entire period from the Week of Saints to the day of Peter and Paul. This fast is needed not only to subdue the flesh and become better but also to preserve within oneself the joy received during Pentecost and Easter.