“Save the date!” in big, red letters. Then it tells you that Christ is returning on May 21. Their message is simple: The Bible says God warned Noah, Jonah, Lot and Moses about the exact time of destructive Old-Testament events. So they think God also warned modern Christians by establishing a predictive timeline via genealogies and historical dates in the Bible.

http://blog.seattlepi.com/thebigblog/2011/04/27/save-the-date-signs-advertise-return-of-jesus-on-may-21/