I came upon this topic after finding at the Canadian naval mounment in Halifax for those lost at sea during WWI and WII that there were naval personnel lost during 1947. Furthermore, the record of military deaths on the Canadian Government's website goes from 1939-1947. I could not find any record of battle or even accidents during 1947 in the Canadian military. Does anyone know what caused Canadian military deaths during 1947 and why these deaths are counted as deaths during WII even though the war ended in 1945?
The Canadian government keeps records of military deaths from World War 2 up to 1947 which include (emphasis added):
those killed in action
those who died as a result of accident or illness while in service
those who subsequently died of injuries related to service
So an individual who was injured in, say, 1945, who passed away in 1947 would be counted as someone who died during WW2. To a certain extent, the selection of 1947 was somewhat arbitrary - as another date could have been selected.
As noted by u/Makgraf, service member deaths from 3 September 1939 to 31 December 1947 were considered war deaths and thus recorded by the Canadian government. These casualties are also commemorated by the Commonwealth War Graves Commission (known as the Imperial War Graves Commission from 1917 to 1960) and it was actually this organisation which shaped the definition of war dead.
1947 both is and isn’t an arbitrary date – it is arbitrary in the sense that the date doesn’t really represent anything (such as the end of the war or the signing of treaties) but there is also a reason behind it being chosen. 31 December 1947 was chosen as the cut-off date to reflect a precedent set during the First World War, when the Imperial War Graves Commission (IWGC) was established. For the First World War, to be considered war dead (and thus commemorated by the IWGC) a service member had to have died (due to military service or causes attributable to service) between 4 August 1914—when the British Empire declared war—and 31 August 1921—the official end of war for the British Empire as per an order in council. For the Second World War, it was decided that, for the purposes of the IWGC, the end date of the war would follow the precedent of the First World War. Thus, 31 December 1947 was chosen because it was approximately the same number of days after VE Day as 31 August 1921 had been after 11 November 1918.
Broadly, causes of death varied from dying of wounds and disease to accidents. If you want to look at specific causes of death, you can cross-reference war dead found on the Commonwealth War Graves Commission website (you can search by year of death, military served with, etc.) with service files (available online at Library and Archives Canada) or the records of Second World War service members who died in Canada (RG 150, 1992-93/314, volumes 279 to 302, Library and Archives Canada; available on Ancestry.ca).
Sources:
Commission Meeting No. 42, February 1922, CWGC/2/2/1/42
Commission Meeting No. 292, May 1947, CWGC/2/2/1/292
Commission Meeting No. 295, September 1947, CWGC/2/2/1/295