(Wikipedia) International Talk Like a Pirate Day (ITLAPD) is a parodic holiday invented in 1995 by John Baur (Ol' Chumbucket) and Mark Summers (Cap'n Slappy), of Corvallis, Oregon, who proclaimed September 19 each year as the day when everyone in the world should talk like a pirate. For example, an observer of this holiday would greet friends not with "Hello," but with "Ahoy, me hearty!" The holiday, and its observance, springs from a romanticized view of the Golden Age of Piracy.
According to Summers, the day is the only holiday to come into being as a result of a sports injury. He has stated that during a racquetball game between Summers and Baur, one of them reacted to the pain with an outburst of "Aaarrr!", and the idea was born. That game took place on June 6, 1995, but out of respect for the observance of D-Day, they chose Summers' ex-wife's birthday, as it would be easy for him to remember.
At first an inside joke between two friends, the holiday gained exposure when John Baur and Mark Summers sent a letter about their invented holiday to the American syndicated humor columnist Dave Barry in 2002. Barry liked the idea and promoted the day. Growing media coverage of the holiday after Barry's column has ensured that this event is now celebrated internationally, and Baur and Summers now sell books and T-shirts on their website related to the theme.
How to Talk Like a Pirate