I understand in the Middle Ages people thought the world would end when the year 1000 began. Some people thought that about the year 2000 and Y2K scared lots of folks for practical reasons. Then Mr. Camping predicted the Second Coming of Christ, and lots of people actually believed the world would end at the end of the Mayan Calendar.
Besides dates and numbers to worry about there have been many others people thought were lucky, or at least interesting. Babies were born on 12/12/12 to great acclaim and lots of people scheduled weddings on that day because they thought it would bring them good luck.
But the dates with interesting patterns aren't over. Today is 1/2/12, next year there will be a 1/3/13, then 1/4/14 and so on for the rest of the decade - assuming, of course, that the world doesn't end in the meantime. ;-)
But there's one more interesting date this year that won't be repeated for a long time. In the Fall 11/12/13 will be the last date with that pattern in the twenty-first century.