We know only what Allah has told us but we can’t elaborate on the nature of such a thing as it is unseen to us and it is beyond our comprehension.
Things will change and be different to what we know. Allah says: “And they ask you to hasten on the torment! And Allâh fails not His Promise. And verily, a day with your Lord is as a thousand years of what you reckon”22:47
This means that only Allah knows about the nature of such days, whether 1,000 or 50,000 years.