At 12.10 a.m. a British bomber went over; searchlights came out and it gave the identity signal - two Verey lights, one red, one yellow. Warning at 12.25 a.m. Bomber over London from N. to S. dropping bombs which made violet flashes: two shells fired at it. Several others followed it. All clear came at 4 a.m. // 1 Sun. Continued. Warm glorious sunny day; warm even at night. Surprised that such a day could be. Warning from 11.10 to 11.40 a.m. Also from 2 to 2.50 p.m. Air battle over Croydon. Heard sound of machine guns & saw puffs of bursting shells high up over the raiders. Miss Hilliard came to tea; gave her some roses.
On this day: this month will see German E-boat (i.e. motor torpedo boat) operations increase off Britain's east coast. At this stage, most loses are sustained in the Irish Sea, from night surface attacks by U-boats (Unterseeboot, i.e. submarines).