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.

Example input: Passage: The French and Indian War (1754–1763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict.
Example output: When was the French and Indian War?
Example explanation: This question is based on the following sentence in the passage- The French and Indian War (1754–1763) was the North American theater of the worldwide Seven Years' War. It is a common convention to write (start year-end year) beside a historical event to understand when the event happened. You can ask questions like this one about dates, years, other numerals, persons, locations, noun phrases, verb phrases, adjectives, clauses etc. which exist in the paragraph.
Q: According to filings to the Canadian Radio-television and Telecommunications Commission (CRTC) by Thunder Bay Electronics (owner of CBC's Thunder Bay affiliate CKPR-DT) and Bell Media (owner of CBC affiliates CFTK-TV in Terrace and CJDC-TV in Dawson Creek),[citation needed] the CBC informed them that it will not extend its association with any of its private affiliates beyond August 31, 2011. Incidentally, that was also the date for analogue to digital transition in Canada. Given recent practice and the CBC's decision not to convert any retransmitters to digital, even in markets with populations in the hundreds in thousands, it is not expected that the CBC will open new transmitters to replace its affiliates, and indeed may pare back its existing transmitter network. However, in March 2011, CKPR announced that it had come to a programming agreement with the CBC, in which the station will continue to provide CBC programming in Thunder Bay for a period of five years. On March 16, 2012, Astral Media announced the sale of its assets to Bell Media, owners of CTV and CTV Two, for $3.38 billion with CFTK and CJDC included in the acquisition. Whether the stations will remain CBC affiliates or become owned-and-operated stations of CTV or CTV Two following the completion of the merger is undetermined.
A:
What was Canada's date for the switch between analog and digital transmission?