It was a Wednesday.
Dec 31 2013 is a Tuesday.
Friday
Tuesday
Wednesday
December 31, 1953 was a Thursday.
December 31, 1959 fell on a Thursday.
It was a Friday.
December 31st, 1985 fell on a Tuesday.
October 31st, 1986 fell on a Friday. The following year, it fell on a Saturday.
yes
December 31, 1990 was Monday.
1986 (as of Dec 29th 2013) unless your DOB is dec 30 or 31