I've heard it my entire life and he still hasn't showed up. Do they even know what they're talking about?
2 Peter 3 v 8-9 reads:-
BUt do not forget this one thing, dear friends: With the Lord a day is like a thousand years, and a thousand years are like a day. The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance.’