Swedenborg says that that days in the Bible – and other measurements of time – represent spiritual states, or specific phases in our spiritual development. So when it says “the end of days” it means the end of one spiritual state and a time of transition to a new one. This is also stated as “the process of time” in some cases, and the phrasing can vary according to the translation.
Passages from Swedenborg
Arcana Coelestia (Elliott) n. 346
346. Verse 7 And it happened at the end of days that Cain brought some of the fruit of the ground, a gift for Jehovah. ‘The end of days’ is used to mean the course of time, ‘fruit of the ground’ the works of faith devoid of charity, and ‘a gift for Jehovah’ worship deriving from this.
Arcana Coelestia (Elliott) n. 6337
6337. ‘And I will show you what will happen to you at the end of days’ means the nature of the Church’s state within the order in which they were arranged at that time. This is clear from the meaning of ‘showing what will happen’ as communicating and foretelling; and from the meaning of ‘theend of days’ as the final phase of the state in which they exist together – ‘days’ being states, 23, 487, 488, 493, 893, 2788, 3462, 3785, 4850, and ‘the end’ the final phase, so that ‘the end of days’ is the final phase of a state, that is to say, of the state in which truths and forms of good in general exist together when arranged in their proper order.
Arcana Coelestia (Elliott) n. 347
347. That ‘the end of days’ is used to mean the course of time maybe clear to anyone. In its earliest form, when simplicity was still present in it, this doctrine called Cain does not seem to have been so unacceptable as it was later on. This is clear from the fact that they called offspring ‘Gained a man, Jehovah’; so in its earliest form faith was not separated so much from love as it was ‘at the end of days’, or in the course of time, as usually happens with all doctrine that belongs to true faith.