23. Nothing is more common in the Word than for "day" to be used to denote time itself. As in Isaiah:
The day of Jehovah is at hand. Behold, the day of Jehovah cometh. I will shake the heavens, and the earth shall be shaken out of her place: in the day of the wrath of Mine anger. Her time is near to come, and her days shall not be prolonged (Isa. 13:6, 9, 13, 22).
And in the same Prophet:
Her antiquity is of ancient days. And it shall come to pass in that day that Tyre shall be forgotten seventy years, according to the days of one king (Isa. 23:7, 15).
As "day" is used to denote time, it is also used to denote the state of that time, as in Jeremiah:
Woe unto us, for the day is gone down, for the shadows of the evening are stretched out (Jer. 6:4).
And again:
If ye shall make vain My covenant of the day, and My covenant of the night, so that there be not day and night in their season (Jer. 23:20, also 25).
And again:
Renew our days, as of old (Lam. 5:21).