'Days' in the Bible

But [in those days] false prophets arose among the people, just as there will be false teachers among you, who will subtly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction on themselves.

Knowing this first, that there shall come in the last days scoffers, walking after their own lusts,

But in taking this view they put out of their minds the memory that in the old days there was a heaven, and an earth lifted out of the water and circled by water, by the word of God;