Saturday.
August 23rd, 1995 fell on a Wednesday.
August 23rd, 1942 fell on a Sunday.
Thursday
August 23rd 1942 was a Sunday.
August 23, 1993 was a Monday.
August 23, 1950 fell on a Wednesday.
August 23rd, 1975 fell on a Saturday.
August 23rd 1953 was a Sunday.
August 11th, 2014 will fall on a Monday.
The 9th of August can occur on any day of the week. As the question was asked in July 2014, it is possible you were referring to August of 2014, in which case the answer is Saturday.
23rd August 1971 was a Monday.
August 23rd, 1973 fell on a Thursday.