You've undoubtedly spent a June 11th in the past recovering from excessive celebration of "National Ballpoint Pen Day." Like most Americans, you probably overdid the June 10th observance of this special holiday by consuming one too many Black Cows (root beer floats for the uninitiated few) and iced teas that share their "national day" status with the ballpoint pen.
Why do we celebrate this very useful writing instrument on June 10th? Well, it is widely circulated as the day back in 1943 that the Hungarian Bíró brothers, Laszlo and György, filed European Patent #2390636 to protect their invention of what is considered the "modern" ballpoint pen. Their invention like many others was to solve a problem. Laszlo's position as a newspaper editor had him wanting for a writing instrument that could dispense a quick drying ink reducing the problem of smudging. He enlisted the help of György, a dentist up on his chemistry, to develop the delivery of a viscous ink to a mechanism that employed a rolling ball held in a socket. For more on how a ballpoint pen works, see Will a Ballpoint Pen Work in Space? Yet did you quaff all those Brown Cows and iced teas in joint celebration with the ballpoint pen by mistake? Perhaps.
For one reason, some argue the ballpoint pen was really invented by another guy frustrated in his work. John J. Loud was a leather tanner looking for a way to mark his leather for cutting that was less messy than a fountain pen. On October 30, 1888, he filed his patent for a pen that delivered ink by the same ball and socket mechanism. Hairsplitters will argue of course that Loud's pen was only a coarse precursor to the modern ballpoint and subject to some of the same failings shared by many other stabs at inventing the marketable modern ballpoint pen.
The second and third reasons you may be in luck if you missed the opportunity to celebrate on June 10th is the Bíró brothers filed patents on June 15th, 1938, in Britain (perhaps France as well) and on June 17th, 1943, in the United States.
So, I'm at a loss for why June 10th is National Pen Day or why something "mightier than the sword" must share its day with beverages. It seems perfectly within reason to celebrate the ballpoint pen alone and anew on June 15th or 17th. Happy doodling!