Today marks the last time most people will see the date, month and year all use the same number.
Shorthand for today's date is 12/12/12 and, while something similar has happened every year since 2001, this will mark the last time this century. There is no 13th month in the calendar.
The number 12 has long had implications for religious numerology. There were 12 Olympians in the ancient Greek pantheon. The Bible records Jacob as having 12 sons, founders of the 12 tribes of Israel. The New Testament lists 12 apostles of Jesus.
The 12 nights between Christmas and Epiphany are called the 12 days of Christmas.
Shi'a Islam includes groups dubbed "twelvers," who believe there were 12 imams who were legitimate successors to Muhammed.
Need something newer? The Church of Jesus Christ of Latter Day Saints, commonly known as the Mormons, has a Quorum of the Twelve Apostles.
Of course, not all uses are religious. Both the western and Chinese zodiacs have 12 signs. Fans both in American football and soccer are sometimes called the "12th Man." You need 12 strikes if you ever hope to bowl a perfect game.
King Arthur had 12 knights at the round table. Most people have 12 pairs of ribs. Juries commonly have 12 members, thus Henry Fonda's eponymous "12 Angry Men."
Reading this on a computer? Look down at your keyboard. There's a good chance it has 12 function keys: F1 through F12.
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