This Guinness ad appeared on Bloomsday on social media in Ireland. Bloomsday is a celebration that takes place both in Dublin and around the world. It celebrates Thursday 16 June 1904, which is the day depicted in James Joyce’s novel Ulysses. It’s a day of huge celebration of Ireland’s most famous writer, whose books have changed the history of literature across the world forever. And this ad unites two of Ireland’s greatest icons.