In your part of the world was World War 2 1937-1945 1939-1945 1941-1945?

1939-1945 are the generally accepted dates for WW2 (I'm Canadian but this is true for most "the west").  For the Americans it was 1941-45 (they conveniently forget about the parts before they joined in).  For China it was 1937-45 ("the west" generally tends to forget about Manchuria).

Canada:  1939-1945.

The actual starting date in practice is 1931 when Japan starts going on the offensive in Manchuria.  

For the USA it was December 7, 1941 to September 2, 1945.

Here in Canada, we did not declare war on Germany until Sept. 10, 1939, as the week earlier, Parliament was not in session and all the members had to be called back to Ottawa for the vote.

My mother was at the time in the USSR, so for her, it didn't start until June 22, 1941.

In my part of the world it was June 1942 to July 1943 and it was over and moved on.

Britain warned Germany if they invaded Poland then a state of war would exist between them. On 3 September 1939 war was declared because Germany had invaded Poland.

On 7 December 1941 Japan bombed Pearl Harbour and 4 days after that on 11 December 1941 the USA entered WW2.

War in Europe commenced 3 September 1939 when Britain declared war on Germany and on 11 December 1942 when the USA entered the war it became WW2 because war also existed between the USA and Japan.

so in reality WW2 did actually commence on 11 December 1941 and prior to that the war was confined to Europe.

I personally doubt that if Japan had not bombed Pearl Harbour the USA would never have become involved in the war in Europe.

Another thing is that when the USA entered the war Britain and her other allies did not wait 2 years before coming to the aid of the USA and they immediately joined the war against Japan and fought side by side with the USA.