This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

On May 1, 1953, ABC's New York City flagship stations – WJZ, WJZ-FM and WJZ-TV – changed their respective callsigns to WABC, WABC-FM and WABC-TV, and moved their operations to facilities at 7 West 66th Street, one block away from Central Park. The WABC call letters were previously used by the flagship station of CBS Radio (now WCBS (AM)) until 1946. The WJZ calls would later be reassigned to the then-ABC affiliate in Baltimore in 1959, in an historical nod to the fact that WJZ was originally established by the Baltimore station's owner at the time, Westinghouse.
When did ABC's New York flagship stations change their call signs?