The « jour de la promesse » was employed by Michel de Notre-Dame, also known as Nostradamus. It also known as the Judgment Day from the Apocalypse texts. When the seven seals will be broken, the seven angels will bring chastisements of God. God will open the book of Wrath on the human beings corrupters and destroyers.

In the X/1999, the “jour de la promesse” is the day of the final battle between the Seven Seals and the Seven Angels (01/09/1999). The destiny is foreordained: the Dragons of Heaven will be destroyed and the Dragons of Earth will destroy all humanity in order to make rebirth the Earth.

The “jour de la promesse” starts when Kamui Shiro unseals the Sacred Sword kept inside Clamp School.