For a larger perspective, see Timeline of World War II.
Sweden intercepts, and tries to decipher, the German teleprinter communications.
Beginning of the drawn out conflict over the Kvarstad vessels, Norwegian trade vessels that were trapped in Swedish harbors at the start of the invasion.
Both the Allies and Germany claimed ownership of the vessels throughout the war.
According to international treaties, Governments in exile are not allowed to exercise their legal powers from a neutral nation.