Passage: In 1910, Kurfürst Friedrich Wilhelm was sold to the Ottoman Empire and renamed Barbaros Hayreddin. She saw heavy service during the Balkan Wars, primarily providing artillery support to Ottoman ground forces in Thrace. She also took part in two naval engagements with the Greek Navy — the Battle of Elli in December 1912, and the Battle of Lemnos the following month. Both battles were defeats for the Ottoman Navy. In a state of severe disrepair, the old battleship was partially disarmed after the Ottoman Empire joined the Central Powers early in World War I. On 8 August 1915 the ship was torpedoed and sunk off the Dardanelles by the British submarine HMS E11 with heavy loss of life.

Question: What date did the battle of Elli take place?
December 1912