Everything you need to know about this wondrous holiday is on this link:
http://en.wikipedia.org/wiki/X-Day_(Church_of_the_SubGenius)
Here’s my favorite excerpt:
When July 5, 1998 arrived and no alien fleet appeared in the sky, members of the Church began citing a large number of conspiracy theories to explain why the predicted end of the world did not take place. The manual page of the ddate program claims that the Church “declared that it had got the year upside down” and that X-Day will actually take place in 8661.
I actually laughed out loud when I read that. Diana wondered why I was laughing. It is also a number of other holidays today, like New York City celebrates emancipation day! But i don’t know how to draw that.
A Cause to Celebrate 