On June 16th, 1904, the fictional Leopold Bloom set out on the most plain day of his entire life, and literature lovers across the world have been celebrating it for almost a century.

It is the only international holiday designated solely to a single work of art.

“Bloomsday,” named after the protagonist of James Joyce’s novel Ulysses, is observed to recall both the ordinary Irishman that is the character, but also the extraordinary Irishman who penned him in the early 20th century.

Joyce first published Ulysses as a serialized novel in the 1910s, and then as a single volume in 1922. Within two years, it accumulated a wide-reaching reputation as the definitive modernist novel, informing the young careers of writers as diverse as Jorge Luis Borges and Salman Rushdie.

Bloomsday celebrations in over a dozen countries include marathon readings of Joyce’s work, dressing in Edwardian garb, full Irish breakfasts, and visits to some of the locales featured in the book. In Dublin, Joyce’s hometown and the primary setting of the novel, fans retrace Bloom’s walking route throughout the city, with pitstops for stout and recitation.

What does Philly do?

Well, the city’s Rosenbach Museum and Library is home to Joyce’s original Ulysses manuscript, and has hosted one of the world’s largest Bloomsday celebrations with a week-long festival of lectures, readings, and reenactments along Delancey Place.

Though published in 1922, Ulysses was banned in the United States for “obscenity” until 1934. The US Postal Service seized and burned hundreds of illegal copies throughout the 1920s. The novel’s few lewd scenes are considered tame by today’s standards.

Other fun facts? Joyce chose June 16th to set his masterpiece because it was the day on which he went on his first date with his future wife, Nora Barnacle. If you want some understandable obscenity, check out the author’s love letters to his wife.

Fans have also tried to grow Joyce’s audience into the digital era. On Bloomsday in 2011, some “Joyce-sodden tweeps” conducted a social media experiment to Tweet the novel throughout its observation day. The results were less than grand, but if the last century has shown us anything, it's that respect for Joyce's work is enduring.