It was a Wednesday.
September 14, 1944 was a Thursday.
Tuesday
September is a whole months, so it couldn't have fallen on any day of the week. The first day of September (in 1994) was on Thursday, and the 30th was on a Friday.
September 14th 1971 was a Tuesday.
September 14th, 1982 was a Tuesday.
September 14th, 1970 fell on a Monday.
14th February 1939 was a Tuesday.
December 14th 1915 was a Tuesday.
August 14th, 2058 will fall on a Wednesday.
September 14th, 1941 was a Sunday.
September 14th 1956 was a Friday.
That date can be interpreted in two ways, depending on where you are in the world. The 9th of November 1994 was a Wednesday. September the 11th 1994 was a Sunday.