Hyderabad
On 1 November 1956 the states of India were reorganised by language. Hyderabad state was split into three parts, which were merged with neighbouring states to form the modern states of Maharashtra, Karnataka and Andhra Pradesh. The nine Telugu- and Urdu-speaking districts of Hyderabad State in the Telangana region were merged with the Telugu-speaking Andhra State to create Andhra Pradesh, with Hyderabad as its capital. Several protests, known collectively as the Telangana movement, attempted to invalidate the merger and demanded the creation of a new Telangana state. Major actions took place in 1969 and 1972, and a third began in 2010. The city suffered several explosions: one at Dilsukhnagar in 2002 claimed two lives; terrorist bombs in May and August 2007 caused communal tension and riots; and two bombs exploded in February 2013. On 30 July 2013 the government of India declared that part of Andhra Pradesh would be split off to form a new Telangana state, and that Hyderabad city would be the capital city and part of Telangana, while the city would also remain the capital of Andhra Pradesh for no more than ten years. On 3 October 2013 the Union Cabinet approved the proposal, and in February 2014 both houses of Parliament passed the Telangana Bill. With the final assent of the President of India in June 2014, Telangana state was formed.

Q: What date was the official formation of Telangana state?
June 2014