OK, I did a quick search, here is the answer regarding 12-31-46
http://www.nytimes.com/learning/general/onthisday/big/1231.html#article
Truman Declares Hostilities Ended, Terminating Many Wartime Laws; Republican Chiefs Commend Action
51 Statutes to Die Government’s Power to Seize Plants and 1 1/2 Billion Taxes to Go 18 of Laws End at Once States of Emergency and War Continue-Sudden Action a Surprise to Washington
By BERTRAM D. HULEN
Special to The New York Times
Washington, Dec. 31–President Truman in a surprise proclamation terminated formally the period of hostilities in World War II as of noon today.
The action was announced by the President personally at a suddenly called news conference this forenoon at which he said:
“The time has come when such a declaration can properly be made, and it is in the public interest to make it.”
At the same time he emphasized that the states of emergency that were proclaimed by the late President Roosevelt in 1939 and 1941 and the state of war itself, which presumably will run until peace treatise have been terminated. They would require action by Congress, he pointed out.
The state of hostilities, a term covering the period of actual fighting and one used in defining the duration of many war-time statues, alone was involved in the President’s proclamation, but this served to terminate immediately eighteen emergency laws and scheduled for expiration six months from now or later provisions of thirty-three other statutes.