You will be given a definition of a task first, then some input of the task.
Generate a correct and concise answer for the question based on the words in the context.

Context : The Letters Patent, 1947 (more formally, the Letters Patent Constituting the Office of Governor General and Commander-in-Chief of Canada) are a legal instrument introduced by King George VI, which came into effect on 1 October 1947 and continue to, along with parts of the Constitution Act, 1867, constitute the Office of the Governor General.
Question : The point in time of Letters Patent, 1947 was when?
Output:
1 October 1947