December 12, 2012 is a significant date because it's the last time in the 21st century in which the three numbers for the day, month and year are perfectly aligned, i.e. 12/12/12. Since the month number only goes up to 12, people will have to wait till the next century to see such a unique calendar event again.

December 12, 2012 is especially significant in China because the Chinese pronunciation for the number 12 resembles the sound of the two characters "want" and "love". Consequently, many people from around the country choose this day to get married or to renew their wedding vows.