The first Sunday after Easter in the church calendar is called Antipascha or St. Thomas Sunday. In the people this day is called the Red Hill. The name Antipascha means "instead of Easter" or "the opposite of Easter" - but this is not a contrast, but an appeal to the past holiday, its repetition on the eighth day after Easter.
Since ancient times, the end of the Bright Week has been celebrated in a special way, constituting, as it were, a replacement for Easter. This day is also called St. Thomas' week, in memory of the miracle of the assurance of the Apostle Thomas.
The death of Christ on the Cross made an incredibly depressing impression on the Apostle Thomas: he seemed to have established himself in the conviction that His loss was irretrievable. To the assurances of the disciples about the resurrection of Christ, he answers: “Unless I see the wounds from the nails on His hands and put my hand in His side, I will not believe” (John 20, 25).