The Bhagavad Gita in Chapter 2, Verse 69 describes an enigmatic reversal of day and night in the life of a Yogi.
ya nisha sarva-bhutanam tasyam jagarti samyami
yasyam jagrati bhutani sa nisa pasyato muneh
In ordinary life, the five senses in Man seek to alleviate their thirst by participating in social life. In such cases, the waking consciousness is the day (i.e. the place of activity) while the inner worlds are dark like the night.
In case of a Yogi/Yogini, the situation becomes inverted when the doorways to the subtle worlds are opened because then the inner worlds burn brightly and are full of activity (i.e. the day) while the waking state seems dull and boring (i.e. the night).
Sri Aurobindo’s exposition of this verse:
The status he reaches is the Brahmic condition; he gets to firm standing in the Brahman, brāhmī sthitih. It is a reversal of the whole view, experience, knowledge, values, seeings of earth-bound creatures. This life of the dualities which is to them their day, their waking, their consciousness, their bright condition of activity and knowledge, is to him a night, a troubled sleep and darkness of the soul; that higher being which is to them a night, a sleep in which all knowledge and will cease, is to the self-mastering sage his waking, his luminous day of true being, knowledge and power. They are troubled and muddy waters disturbed by every little inrush of desire; he is an ocean of wide being and consciousness which is ever being filled, yet ever motionless in its large poise of his soul; all the desires of the world enter into him as waters into the sea, yet he has no desire nor is troubled. For while they are filled with the troubling sense of ego and mine and thine, he is one with the one Self in all and has no “I” or “mine”. He acts as others, but he has abandoned all desires and their longings. He attains to the great peace and is not bewildered by the shows of things; he has extinguished his individual ego in the One, lives in that unity and, fixed in that status at his end, can attain to extinction in the Brahman, Nirvana, – not the negative self-annihilation of the Buddhists, but the great immergence of the separate personal self into the vast reality of the one infinite impersonal Existence.
Sri Aurobindo, Essays on the Gita: The Yoga of the Intelligent Will
Sri Aurobindo has also described this reversal in his epic poem Savitri
A vision lightened on the viewless heights,
A wisdom illumined from the voiceless depths:
A deeper interpretation greatened Truth,
A grand reversal of the Night and Day;
All the world’s values changed heightening life’s aim;
A wiser word, a larger thought came in
Than what the slow labour of human mind can bring,
A secret sense awoke that could perceive
A Presence and a Greatness everywhere.