It was a Wednesday.
May 9 1942 was a Saturday.
Friday
From a US perpetual calendar: August 9, 1942 was on Sunday.
December 9, 2007 was a Sunday.
December 9 1951 was a Sunday.
December 9 2010 was a Thursday.
9 December 1979 was a Sunday.
December 9 1963 was a Monday.
December 9, 1964 fell on a Wednesday.
December 9 1970 fell on a Wednesday
December 9, 2009 fell on a Wednesday.
December 9, 1997 fell on a Tuesday.