The only reference point i have is that the millennium was very roughly around 1000000000. And that's only because of an agonising C/Prince pun in NTK [1]:
I don't know whether to thank or revile you for sharing that link. I've never heard of NTK before and I was at once amazed at something that tickled me so and also realizing it's no longer around. Now I feel sad.
"Tonight I'm gonna party like it's (time_t) 1E9"
[1] http://www.ntk.net/2001/02/23/