Explanation:

• The RBI commenced its operations on April 1, 1935, with Sir Osborne Smith as its first Governor. At that time RBI followed a January-December accounting year. Later in 1940, the bank changed its accounting year to July-June. 
• Now the RBI is making another switch -  the next accounting year will be a nine-month period from July 2020 to March 31, 2021 and thereafter, all financial years will start from April, as it happens with the central and state governments.

Establishment

• The Reserve Bank of India was established on April 1, 1935 in accordance with the provisions of the Reserve Bank of India Act, 1934.
• The Central Office of the Reserve Bank was initially established in Calcutta but was permanently moved to Mumbai in 1937. The Central Office is where the Governor sits and where policies are formulated.
• Though originally privately owned, since nationalisation in 1949, the Reserve Bank is fully owned by the Government of India.
• The Preamble of the Reserve Bank of India describes the basic functions of the Reserve Bank as:"to regulate the issue of Bank notes and keeping of reserves with a view to securing monetary stability in India and generally to operate the currency and credit system of the country to its advantage; to have a modern monetary policy framework to meet the challenge of an increasingly complex economy, to maintain price stability while keeping in mind the objective of growth.”