2 Peter 3:5-8

They deliberately forget that God made the heavens long ago by the word of his command, and he brought the earth out from the water and surrounded it with water. Then he used the water to destroy the ancient world with a mighty flood. And by the same word, the present heavens and earth have been stored up for fire. They are being kept for the day of judgment, when ungodly people will be destroyed. But you must not forget this one thing, dear friends: A day is like a thousand years to the Lord, and a thousand years is like a day.