Arthur's Day refers to annual series of music events worldwide, first organised by Diageo in 2009 to promote the 250th anniversary of its Guinness brewing company.
Guinness (// gin-is) is a popular Irish dry stout that originated in the brewery of Arthur Guinness (1725–1803) at St. James's Gate, Dublin. Guinness is one of the most successful beer brands worldwide. It is brewed in almost 60 countries and is available in over 100. Annual sales total 850 million litres (1.5 billion imperial or 1.8 billion US pints).