Tuesday
There are two answers to that, depending on how the date is interpreted. The 10th of August 1939 was on a Thursday. October the 8th 1939 was a Sunday.
August 8 1939 was a Tuesday.
August 30 1939 was on a Wednesday.
29 August 1939 was a Tuesday.
August 27, 1939, was a Sunday.
August 18, 1939 fell on a Friday.
August 14, 1939 fell on a Monday.
August 17, 1939 fell on a Thursday.
Friday
Wednesday
Tuesday
August 8th, 1991 fell on a Thursday.