Zamenhof Day (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". Zamenhof Day Zamenhof Day (), 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
Ludwik Hirszfeld Ludwik Hirszfeld Ludwik Hirszfeld (5 August 1884 in Warsaw – 7 March 1954 in Wrocław) was a Polish microbiologist and serologist. He is considered a co-discoverer of the inheritance of ABO blood types. He was a cousin of Aleksander Rajchman, a Polish mathematician, and of Ludwik Rajchman, a Polish bacteriologist. After attending the Gymnasium in Łódź, Hirszfeld, born into a Jewish family and later a convert to Catholicism, decided to study medicine in Germany. In 1902 he entered the University of Würzburg and transferred in 1904 to Berlin, where he attended lectures in medicine and philosophy. Hirszfeld completed his doctoral