Pope Leo X had that vision on October 13, 1884. The 13th of October is also the date Our Blessed Mother appeared to the Fatima children in 5 of Her 6 apparitions to them. The lone exception was when the children were imprisoned.
Tomorrow is October 13th.
Prayers for tomorrow will be great, in the finest sense of the word. Peace be with you.
I believe RitaOK may have confused popes. Pope Paul VI in 1972 spoke in a sermon about the smoke of Satan entering the tabernacle of God. Leo XIII is said by some sources to have had a vision of the future and the wars and evils to come in the 20th ceturty. Some say he also saw Satan speaking to our Lord, claiming he could destroy the Church if he were given more power and a hundred years in which to do it. This thought by some to be the event that moved Leo to write the Prayer of St. Michael, and to instruct congregations at the end of Mass.