Juha-Matti Laurio writes to point out a Washington Times story about how special this particular Friday the 13th is. The digits in the numerical notation for the date add up to 13 — whether you write it in the US or the European form. From the article: "The phenomenon hasn't happened in 476 years, said Heinrich Hemme, a physicist at Germany's University of Aachen who crunched the numbers to find that the double-whammy last occurred Jan. 13, 1520."