Task: Question Generation
Input (English): CBC announced on April 4, 2012, that it will shut down all of its approximately 620 analogue television transmitters on July 31, 2012 with no plans to install digital transmitters in their place, thus reducing the total number of the corporation's television transmitters across the country down to 27. According to the CBC, this would reduce the corporation's yearly costs by $10 million. No plans have been announced to use subchannels to maintain over-the-air signals for both CBC and Radio-Canada in markets where the corporation has one digital transmitter. In fact, in its CRTC application to shut down all of its analogue television transmitters, the CBC communicated its opposition to use of subchannels, citing costs, amongst other reasons.
Output (English): When did the CBC announce service would be discontinued to analogue transmitters?