I will now quote from THE SPIRITUAL CANTICLE by St. John of the Cross-
"22. The tranquil night
In this spiritual sleep in the bosom of the Beloved, the soul possesses and relishes all the tranquility, rest, and quietude of the peaceful night; and she receives in God, together with this peace, a fathomless and obscure knowledge. As a result she says that her Beloved is a tranquil night to her.
23. At the time of the rising dawn.
Yet she does not say that the tranquil night is equivalent to a dark night, but rather, that is like the night that has reached the time of the rising dawn. This quietude and tranquility in God is not entirely obscure to the soul as is a dark night; but it is a tranquility and quietude in divine light, in the new knowledge of God, in which the spirit elevated to the divine light is in quiet.
She very appropriately calls this divine light "the rising dawn," which means the morning. Just as the rise of morning dispels the darkness of night and unveils the light of day, so this spirit quieted and put to rest in God, is elevated from the darkness of natural knowledge to the morning light of the supernatural knowledge of God. This morning light is not clear, as was said, but dark as night at the time of the rising dawn. Just as the night at the rise of dawn is not entirely night or entirely day, but is, as they say, at the break of day, so this divine solitude and tranquility, informed by the divine light, has some share in that light, but not its complete clarity.
24. In this tranquility the intellect is aware of being elevated, with strange newness, above all natural understanding to the divine light, just as person who after a long sleep opens his eyes to the unexpected light." St. John of the Cross