May 13 is Frog Jumping Day, a holiday of uncertain origin which some claim can be traced back to Hartford's own Mark Twain. Twain's short story Jim Smiley and His Jumping Frog (also titled The Celebrated Jumping Frog of Calaveras County or The Notorious Jumping Frog of Calaveras County) was first published in 1865.
The date of May 13 has no apparent significance to either the author's Mark Twain persona or his real identity of Samuel Clemens. Nor is it mentioned in the story, set in the Angels Camp mining settlement - now the city of Angels Camp - in Calaveras County, California. This weekend, however, is the Calaveras County Fair and Jumping Frog Jubilee.
How Frog Jumping Day is meant to be observed by those who can't make it to Calaveras County is not entirely clear either. Suggestions range from jumping like a frog to acquiring a pet frog to volunteering with an organization that helps care for frogs in the wild. An easier (and certainly less messy) way to commemorate the occasion is to read Twain's story, about bet-happy Jim Smiley, his frog Dan'l Webster, and a wily (and by modern-day standards, amphibian-abusing) stranger.