Synaxis of the Holy Powder (or manna) which emitted from the tomb of Saint John the Theologian

The Gospel According to John 19:25-28, 21:24-25

At that time, standing by the cross of Jesus were his mother, and his mother's sister, Mary the wife of Clopas, and Mary Magdalene. When Jesus saw his mother, and the disciple whom he loved standing near, he said to his mother, "Woman, behold, your son!" Then he said to the disciple, "Behold, your mother!" And from that hour the disciple took her to his own home. This is the disciple who is bearing witness to these things, and who has written these things; and we know that his testimony is true. But there are also many other things which Jesus did; were every one of them to be written, I suppose that the world itself could not contain the books that would be written.