It was on a Thrusday, if you don't believe me then follow this link
http://www.hf.rim.or.jp/~kaji/cal/cal.cgi?1958
April 11, 1958, was a Friday.
11 November 1958 was a Tuesday.
August 11, 1958 fell on a Monday.
November 11, 1958 fell on a Tuesday.
May 11, 1958 fell on a Sunday.
Thursday.
The 11th of September 1958 was a Thursday.
11 December 1965 was a Saturday.
29 November 1958 was on a Saturday.
September 11th, 1958 fell on a Thursday.
December 11 2010 was a Saturday.
December 11 1968 was a Wednesday.