On 1 November 1907, Kafka was hired at the Assicurazioni Generali, an insurance company, where he worked for nearly a year. His correspondence during that period indicates that he was unhappy with a work schedule—from 08:00 until 18:00—that made it extremely difficult to concentrate on writing, which was assuming increasing importance to him. On 15 July 1908, he resigned. Two weeks later, he found employment more amenable to writing when he joined the Worker's Accident Insurance Institute for the Kingdom of Bohemia. The job involved investigating and assessing compensation for personal injury to industrial workers; accidents such as lost fingers or limbs were commonplace, owing to poor work safety policies at the time. It was especially true of factories fitted with machine lathes, drills, planing machines and rotary saws, which were rarely fitted with safety guards.The management professor Peter Drucker credits Kafka with developing the first civilian hard hat while employed at the Worker's Accident Insurance Institute, but this is not supported by any document from his employer. His father often referred to his son's job as an insurance officer as a Brotberuf, literally "bread job", a job done only to pay the bills; Kafka often claimed to despise it. Kafka was rapidly promoted and his duties included processing and investigating compensation claims, writing reports, and handling appeals from businessmen who thought their firms had been placed in too high a risk category, which cost them more in insurance premiums. He would compile and compose the annual report on the insurance institute for the several years he worked there. The reports were well received by his superiors. Kafka usually got off work at 2 P.M., so that he had time to spend on his literary work, to which he was committed. Kafka's father also expected him to help out at and take over the family fancy goods store. In his later years, Kafka's illness often prevented him from working at the insurance bureau and at his writing. Years later, Brod coined the term Der enge Prager Kreis ("The Close Prague Circle") to describe the group of writers, which included Kafka, Felix Weltsch and him.In late 1911, Elli's husband Karl Hermann and Kafka became partners in the first asbestos factory in Prague, known as Prager Asbestwerke Hermann & Co., having used dowry money from Hermann Kafka. Kafka showed a positive attitude at first, dedicating much of his free time to the business, but he later resented the encroachment of this work on his writing time. During that period, he also found interest and entertainment in the performances of Yiddish theatre. After seeing a Yiddish theatre troupe perform in October 1911, for the next six months Kafka "immersed himself in Yiddish language and in Yiddish literature". This interest also served as a starting point for his growing exploration of Judaism. It was at about this time that Kafka became a vegetarian. Around 1915, Kafka received his draft notice for military service in World War I, but his employers at the insurance institute arranged for a deferment because his work was considered essential government service. He later attempted to join the military but was prevented from doing so by medical problems associated with tuberculosis, with which he was diagnosed in 1917. In 1918, the Worker's Accident Insurance Institute put Kafka on a pension due to his illness, for which there was no cure at the time, and he spent most of the rest of his life in sanatoriums.

Question: when did the yiddish theatre troupe perfom
Answer: October 1911