I found this on The Bad Astronomy blog an it bears repeating.

A list of failed end of the world prophecies
Heres a few of them

About 30 CE: The Christian Scriptures (New Testament), when interpreted literally, appear to record many predictions by Jeshua of Nazareth (Jesus Christ) that God’s Kingdom would arrive within a very short period, or was actually in the process of arriving. For example, Jesus is recorded as saying in Matthew 16:28: “…there shall be some standing here, which shall not taste of death, till they see the Son of Man coming in his kingdom.” In Matthew 24:34, Yeshua is recorded as saying: “…This generation shall not pass, till all these things be fulfilled.” Since the life expectancy in those days was little over 30 years, Jesus appears to have predicted his second coming sometime during the 1st century CE. It didn’t happen. More details.

1000-JAN-1: Many Christians in Europe had predicted the end of the world on this date. As the date approached, Christian armies waged war against some of the Pagan countries in Northern Europe. The motivation was to convert them all to Christianity, by force if necessary, before Christ returned in the year 1000. Meanwhile, some Christians had given their possessions to the Church in anticipation of the end. Fortunately, the level of education was so low that many citizens were unaware of the year. They did not know enough to be afraid. Otherwise, the panic might have been far worse than it was. Unfortunately, when Jesus did not appear, the church did not return the gifts. Serious criticism of the Church followed. The Church reacted by exterminating some heretics. Agitation settled down quickly.

1524: Many astrologers predicted the imminent end of the world due to a world wide flood. They obviously had not read the Genesis story of the rainbow.

1669: The Old Believers in Russia believed that the end of the world would occur in this year. 20 thousand burned themselves to death between 1669 and 1690 to protect themselves from the Antichrist.