31 December 1980 was a Wednesday.
August 31, 1980 fell on a Sunday.
May 31, 1980 fell on a Saturday.
31 December 2001 was a Monday.
31 December 1993 was a Friday.
31 December 1965 was a Friday.
31 December 1931 was a Thursday.
December 31 1976 was on a Friday.
December 31 1982 was on a Friday.
December 31 1999 was a Friday.
December 31, 1968 was a Tuesday.
December 31 1945 was a Monday.
December 31, 2005 was a Saturday.