Given the task definition and input, reply with output. 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.

Because rebroadcast transmitters were not planned to be converted to digital, many markets stood to lose over-the-air coverage from CBC or Radio-Canada, or both. As a result, only seven of the markets subject to the August 31, 2011 transition deadline were planned to have both CBC and Radio-Canada in digital, and 13 other markets were planned to have either CBC or Radio-Canada in digital. In mid-August 2011, the CRTC granted the CBC an extension, until August 31, 2012, to continue operating its analogue transmitters in markets subject to the August 31, 2011 transition deadline. This CRTC decision prevented many markets subject to the transition deadline from losing signals for CBC or Radio-Canada, or both at the transition deadline. At the transition deadline, Barrie, Ontario lost both CBC and Radio-Canada signals as the CBC did not request that the CRTC allow these transmitters to continue operating.
When was CBC's anologue upgrade extension set to expire?