Sunday.
October 21, 1978 fell on a Saturday.
Wednesday
May 21 1970 was a Thursday.
June 21 2000 was a Wednesday.
21 December 1989 was a Thursday.
21 October 1950 was a Saturday.
21 October 1990 was a Sunday.
October 21, 1945 was a Sunday.
October 21 1861 was on a Monday.
October 21 1992 was a Wednesday
October 21, 1999 was a Thursday.
October 21 2010 was a Thursday.
October 21, 1940 was a Monday.
October 21, 1981 was a Wednesday.
October 21, 1995 fell on a Saturday.
October 21, 1921 fell on a Friday.
October 21, 2011 fell on a Friday.