Arcana Coelestia #23
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.
Arcana Coelestia #4780
4780. 'And mourned over his son many days' means a state, namely one of mourning for lost good and truth. This is clear from the representation of Joseph, to whom 'son' refers here, as Divine Truth, specifically the truths spoken of above in 4776; and from the meaning of 'days' as states, dealt with in 23, 487, 488, 493, 893, 2788, 3785, in this case a state of great mourning since the expression 'many days' is used.