That depends whether you celebrate Pi day on 3.14 (March 14) or 22/7 (July 22).
The day of the week was a Saturday.
October 13th, 1975 was a Monday.
May 16 1975 was a Friday.
November 7, 1975 was a Friday.
22 June 1975 was a Sunday.
21 February 1975 was a Friday.
January 22 1975 was a Wednesday.
February 13 1975 was on a Thursday.
November 1st 1975 was a Saturday.
March 1 1975 was a Saturday.
January 26 1975 was a Sunday.
May 3 1975 was a Saturday.