|Official name||Zamenhofa Tago (Esperanto)|
|Also called||Esperanto Literature Day,|
|Observed by||International Esperanto community|
|Next time||15 December 2022|
Zamenhof Day (Esperanto: Zamenhofa Tago, Polish: Dzień Zamenhofa), also called Esperanto Book Day, is celebrated on 15 December, the birthday of Esperanto creator L. L. Zamenhof. It is the most widely celebrated day in Esperanto culture. On this day, Esperantists hold information sessions and cultural gatherings to promote literature in Esperanto.
The history of celebrating Esperanto on Zamenhof's birthday can be traced back to 17 December 1878, when at a birthday party for his 19th birthday he presented to his friends his Lingwe uniwersala, the first version of his international language. By 1887, this language had evolved into what is now recognized as Esperanto when he published the Unua Libro. December 15th previously used to be also known as Esperanto Day, but that is now celebrated on 26 July, the day Unua Libro was published. As of 1927 onwards, December 15th is celebrated within the Esperanto movement as Esperanto Culture Day as it is customary to purchase a new book on Esperanto on that occasion.
Zamenhof's 150th birth anniversary
15 December 2009 marked 150 years since Zamenhof's birth, and there were several events to celebrate. On this date, the authorities in his home town of Białystok, Poland, opened a new Zamenhof Center, and a symposium honoring Zamenhof was held in New York City, featuring talks by Arika Okrent and Humphrey Tonkin among other professors.
Also on this date, the search engine Google, in 33 national language versions (but not the international English one), bore a special version of their logo (a Doodle) emblazoned with the Esperanto flag in honor of the occasion, which generated, on the 30 biggest Wikipedia languages, 1,750,000 page views on the articles "L. L. Zamenhof".
- Keller, Stefano. "Zamenhof-Day / Esperanto Book Day, 15 December". Translated by Moon, Brian. Universal Esperanto Association. Retrieved 14 December 2018.
- Birth certificate of Ludwik Zamenhof Archived 29 February 2012 at the Wayback Machine, dated 15 December 1859, Archives of Poland, Post-Partition Era (19th century). It corresponds to 3 December in the then-official Julian calendar of Russia.
- Pri la 145-a Zamenhofa tago at China Radio International
- Boulton, Marjorie. Zamenhof, Aǔtoro de Esperanto. La Laguna : J. Régulo, 1962. (in Esperanto)
- Discussion on the exact date of that birthday party may be found at Message Board Archived 25 April 2012 at the Wayback Machine at Yahoo Groups Japan
- Limako (15 December 2009). "Esperanto Day at Google". Esperanto-USA.org. Archived from the original on 18 December 2009. Retrieved 14 December 2018.
- "Esperanto Day" (PDF). Universal Esperanto Association. Retrieved 14 December 2018.
- Limako (12 December 2009). "Esperanto Today". Esperanto-USA.org. Archived from the original on 26 December 2009. Retrieved 14 December 2018.
- Zamenhof Symposium
- Zamenhof Honored by Google, Huliq.com. Retrieved 15 December 2009.
- Google festas la Zamenhof-Tagon, Libera Folio Archived 6 March 2016 at the Wayback Machine. Retrieved 15 December 2009.
- Blahuš, Marek. "Google: Reklami Esperanton... sen esperantistoj" Archived 14 May 2011 at the Wayback Machine, La Ondo de Esperanto, 2010, n-ro 2 (184), p.8.
- Media related to Zamenhofa Tago at Wikimedia Commons