Happy 4th of July*

Today is a day to celebrate.  But contrary to popular belief it is not just a day to celebrate America's independence from those rascally British (I love you Great Britain, I really do), it is also a day to celebrate Venn diagrams, those overlapping circles of joy and organization.  It is a young holiday and an obscure one to be sure, but every year it grows in popularity as people across the nation (and certainly soon, across the world) celebrate the beauty of a diagram that shows all possible logical relations between a finite collection of sets (thank you wikipedia).  And so, in honor of Venn Diagram Day, I humbly present my own Venn diagram for the occasion:

Please note that Lewis Carroll was indeed correctly placed in the "Venn diagrams" circle.  

But beware, dear reader, there have been unofficial attempts to celebrate Venn Diagram Day at other times in the year.  While the most logical celebrations might be August 4th or April 4th (the birth and death dates of John Venn respectively), no recognized celebration of Venn Diagram Day has ever occurred on either of these dates.  

2002 is the earliest known reference to Venn Diagram Day:

Exhibit A

Later, in 2006 a celebration of Venn diagrams took place sometime around November 16th:

Exhibit B

Exhibit C 

However, if you read the comments attached to Exhibit B, there is a brief explanation:

It actually started with a simple post from seasecret (the post is locked, otherwise I'd link to it) that simply said "I would like to see some Venn diagrams on my friends page." And we all took the bait. 

Nevertheless, the official celebration of Venn Diagram Day is July 4th and has been so for a number of years.  

So happy Independence Day, happy Venn Diagram Day, happy 4th of July*!

*I've been informed recently that July 4th may also be Venereal Disease Day, but I can neither confirm nor deny the legitimacy of this claim.