23. Nothing is more common in the Word than for the word 'day' to be used to mean the particular time at which events take place, as in Isaiah,

The day of Jehovah is near. Behold, the day of Jehovah comes. I will make heaven tremble, and the earth will be shaken out of its place, on the day of My fierce anger. Its time is close at hand, and its days will not be prolonged. Isaiah 13:6, 9, 13, 22.

And in the same prophet,

Her antiquity is in the days of antiquity. On that day Tyre will be forgotten for seventy years, like the days of one king. Isaiah 23:7, 15.

Since 'day' stands for the particular time it also stands for the state associated with that particular time, as in Jeremiah, Woe to us, for the day has declined, for the shadows of evening have lengthened! Jeremiah 6:4

And in the same prophet,

If you break My covenant that is for the day and My covenant that is for the night, so that there is neither daytime nor night at their appointed time. Jeremiah 33:20, 25.

Also,

Renew our days as of old. Lamentations 5:21.

Morning comes with the rising of the sun, and the sun -- which gives life to the earth with its warmth and light -- represents the Lord in His divinity, bringing spiritual life through love and wisdom. Thus, the morning represents the coming of the Lord into our lives, and all the things that flow from it: the love, joy and enlightenment He brings; the peace and tranquility of passing the spiritual obscurity of night; the anticipation of the learning and usefulness of a new day; and the awareness of The Lord's renewed presence.

(References: Apocalypse Explained 179; Apocalypse Revealed 151; Arcana Coelestia 2333 [1-3], 2540, 2780, 5740, 8211, 8812, 10134, 10200, 10413; True Christian Religion 764 [1-2])