[bigboywooly]

You are given extra renown in that flotilla for that very reason
Everybody is neutral on that date period so any ship you sink is neutral

From the 2.1 update release thread

***August 1939 career starts engineered by Bigboywooly:

GWX now has the ability to start in August 1939

For those choosing to start in the 1st or 2nd flotillas it is recommended you carry out a 4 day shakedown patrol before returning to base on the 4th
This will give you a next patrol date of the 24th August
Plenty of time to sail to your start point
For those wishing to begin in the 7th flotilla you will start at Konigsberg
Stay in the bay and sink the target ships and 2 ship convoy

Do not take any damage or you will miss the war start
You will become an enemy of ALL nations so " ESC " back to port on receipt of message

Upon ending patrol you can either transfer to the 1st or 2nd flotillas

and your next patrol will begin on the 24th August
Good hunting