The New York Times crossword puzzle today had the black squares forming a giant “11”. I didn’t understand the significance at first, but now I do — it’s a reference to today’s date, November 11, 2011. Today is already quite important here in the U.S., because it is Veteran’s Day. But it is also a date that can be written 11.11.11. And for that distinction it doesn’t matter whether you are in the U.S. (where the month comes first) or Europe (where the day comes before the month).
This is probably the second to last time in your lifetime that you will experience a date with matching day, month and year, the next time being December 12, 2012. Unless, that is, you happen to stay alive long enough to see January 1, 2101.
And this is the only date in any century that can be written using only a single digit.
Once you start looking at the numerical patterns of dates, all sorts of possibilities suggest themselves. For example, if you are in the U.S. (where the month comes first) then November 23, 2058 can be written as 11.23.58, the first six number of the Fibonacci series.
I wonder how many other numerically notable dates there are.