Zamenhof Day (15 December): Esperanto Book Day

Zamenhof Day (Zamenhofa Tago or Zamenhof-Tago) is celebrated every year on 15 December, the birthday of L. L. Zamenhof, who published Esperanto in 1887. It is the most widely observed holiday among Esperanto speakers. Since the 1920s the same day has also been Esperanto Book Day (Tago de la Esperanta Libro), when speakers buy, give or present a book in Esperanto.

Zamenhof was born on 15 December 1859 in Białystok, then part of the Russian Empire and now in Poland. Russia still used the Julian calendar, so his birth was registered as 3 December; 15 December is the date in the Gregorian calendar used today.

#Why is 15 December Esperanto Book Day?

The idea is credited above all to the Hungarian writer Julio Baghy (1891–1967), one of the best-known authors of original Esperanto literature. He proposed that Zamenhof's birthday should also celebrate Esperanto culture, and in particular books, to raise the cultural level of the movement. The Esperanto Wikipedia also names other activists who supported the idea, among them Nikolai Nekrasov. Wikipedia in both English and Esperanto dates the Book Day tradition to 1927.

The Universal Esperanto Association promotes the day every year as Zamenhof Day / Esperanto Book Day, with press releases in dozens of languages.

#How do people celebrate Zamenhof Day?

Celebrations are local and informal. There is no central ceremony. Typical activities include:

• Meetings of local clubs – a dinner, a birthday cake or a party, often on the nearest weekend.
• Buying or giving a book in Esperanto – the core Book Day custom. Because the date is close to Christmas, gift exchanges are common.
• Talks about Zamenhof and the history of the language.
• Readings and book launches – presentations of new original works and translations.
• Information events for the public – open days, exhibitions and taster lessons.
• Visits to places linked to Zamenhof, such as his birthplace in Białystok or his grave in the Jewish Cemetery on Okopowa Street in Warsaw.

At the individual level, the simplest way to take part is to read, buy or start one book in Esperanto on 15 December.

#How can a learner celebrate Zamenhof Day?

You do not need a club or a congress to take part. Some simple ideas, in the spirit of Book Day:

• Read one book in Esperanto. For learners, Claude Piron's graded detective story Gerda malaperis! is a classic first novel; see Esperanto literature for more.
• Give a book or a song. Many speakers send friends an Esperanto book, album or poem as a gift.
• Join an event. Local clubs and national associations often hold open meetings around 15 December, and some events take place online.
• Learn something about Zamenhof – his life explains why the language exists. Start with his biography.

The celebrations are truly international: in February 2025, for example, the UEA's magazine Esperanto ran a report on Zamenhof Day events "in all parts of the world".

#Is Zamenhof Day the same as Esperanto Day?

No. Esperanto Day (Esperanto-Tago) is 26 July, the anniversary of the publication of the first Esperanto textbook, the Unua Libro, in Warsaw in 1887. In the past, 15 December was sometimes also called Esperanto Day, but today the two dates are kept apart:

#What happened on Zamenhof's 150th birthday in 2009?

On 15 December 2009 Google replaced its logo with a doodle flying the green Esperanto flag. According to Libera Folio, it first appeared on the Chinese, Japanese and Korean versions of Google, then on many European versions, including Russia, Sweden, Germany and France. Esperantists had campaigned for it by writing to Google.

The anniversary year also saw the city of Białystok open the Ludwik Zamenhof Centre, a cultural centre in his home town, and a symposium in New York honoured him with talks by scholars including Humphrey Tonkin and Arika Okrent.

#Where did the tradition start?

The tradition is older than the language itself. On 17 December 1878, at a party two days after his 19th birthday, the young Zamenhof presented his first draft of an international language, Lingwe uniwersala, to his school friends in Warsaw. Nine years later that project, much revised, became Esperanto. See the history of Esperanto for the full story.

#Is Zamenhof Day an official holiday?

No country observes Zamenhof Day as a public holiday. It is a cultural day of the international Esperanto community. Zamenhof has, however, received official recognition in other ways: UNESCO honoured him on the centenary of his birth in 1959, and in 2015 its General Conference added the 100th anniversary of his death (2017) to its list of anniversaries.

#Common questions

#When is Zamenhof Day?

Every year on 15 December, Zamenhof's birthday in the Gregorian calendar. Many clubs celebrate on the nearest weekend.

#What is Esperanto Book Day?

Another name for 15 December. Esperanto speakers mark it by buying, giving or presenting a book in Esperanto, a custom proposed in the 1920s by the writer Julio Baghy and other activists.

#Did Google make a doodle for Zamenhof?

Yes. On 15 December 2009, for his 150th birthday, Google showed a doodle with the Esperanto flag on many national versions of its homepage.

#What is the difference between Zamenhof Day and Esperanto Day?

Zamenhof Day (15 December) celebrates the creator's birth in 1859. Esperanto Day (26 July) celebrates the publication of the first Esperanto book in 1887.

#How do you say "Happy Zamenhof Day" in Esperanto?

Feliĉan Zamenhofan Tagon! – "Happy Zamenhof Day!" The accusative ending -n is used because the phrase is a wish (short for "I wish you a happy Zamenhof Day").

#Sources

• Universal Esperanto Association (ZPI), Zamenhof Day / Esperanto Book Day, 15 December, text by Stefano Keller, 2017
• Wikipedia, Zamenhof Day and Vikipedio, Zamenhofa Tago
• Esperanto (UEA magazine), issue 1398, February 2025
• Google Doodles, 150th birthday of L. L. Zamenhof
• Libera Folio, "Google festas la Zamenhof-tagon", December 2009