The Battle of Kock, marking the conclusion of the invasion of Poland, concludes with a Polish tactical victory despite a German strategic victory.

Hitler makes a flight to Warsaw and participates in a victory parade held in the now captured Polish capital.

The signing of the Soviet-Latvian Mutual Assistance Treaty grants the Russians access to naval and air bases located in Latvian territory.

Under pressure from the Soviet Union, Latvia is compelled to accept a treaty allowing the establishment of Red Navy bases in its Baltic harbors.

The US Navy Hawaiian Detachment officially opens its operations at Pearl Harbor.