An additional 3 days were added at the beginning of the 40 days of Advent during the 10th century to commemorate the three days that Copts fasted before God awarded them the miracle of moving the Mokattam, which lies within a suburb of Cairo, on the hands of Simon the Tanner during the rule of the Fatimid caliph al-Mu'izz li-Din Allah. Thus the fast of Advent begins on 16 Hathor (November 25, which also falls on 15 Hathor in leap years). The three added days are considered a separate fast rather than part of the fast of Advent.