From Sarah Sundin's blog
Today in World War II History—July 31, 1942: Germans cross River Don in Ukraine. Women’s Royal Canadian Naval Service is established; 7000 will serve in the WRCNS as Wrens.
Canada had been reluctant to bring women into naval service.
FWIW, a relative of mine served in the Wrens during the war, even though it had already taken women into the army and the RCAF. For that reason, the Wrens were actually established slightly after the WAVES.
As a perhaps slightly salacious side note, starting in 1943 the Wrens started publishing their own newspaper, the Tiddly Times. The name came from a British seams nickname for something extra to decorate uniforms, but that was an odd choice of titles for more than one reason.
As a note, it's interesting the extent to which we're reading of the Germans as aggressors trying to conquer the same lands that the Russians are now attempting to conquer 80 years later.
Regarding Case Blue, Hitler reversed his recent order which had taken the 4th Panzer Army away from the attack on Stalingrad and reassigned it, reversing its direction, and creating additional confusion.
The 1st Marine Divisions embarked on US and Australian ships for the invasion of Guadalcanal. US aircraft bombed Japanese airfields on the island.