It seems to have been a Thursday.
4 January 1958 was a Saturday.
November 4, 1958 was a Tuesday.
March 4, 1958, was a Tuesday.
April 4, 1958 fell on a Friday.
October 4th, 1958 was a Saturday.
It was a Sunday.
Saturday
4 September 1947 was a Thursday.
4 September 1943 was a Saturday.
September 4 1969 was a Thursday.
September 4 1975 was a Thursday.
September 4 1973 was a Tuesday.