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.

493. There is no need to pause too long over the consideration that 'days' and 'years mean periods of time and states. Only this need be stated here, that in the world periods of time and measurements to which numbers may be applied are indispensable, for they belong within the ultimate realms of nature. But whenever such application occurs, the numbers of days and years, and also the numbers applied to measurements, mean something which is completely different from periods of time or from measurements, and which is determined by the meaning of the number used, as in the statements about there being six days for work, and the seventh being holy, which are dealt with above; in the statement about a jubilee having to be announced every forty-ninth year and celebrated in the fiftieth; about the tribes of Israel being twelve, the same number as the Lord's Apostles; and about there being seventy elders, the same number as the Lord's disciples. And there are many other examples where the numbers mean some special characteristic completely different from the persons or objects to which they apply. And when completely separated one from the other the states meant by the numbers are then left.