December 8 1955 was a Thursday.
December 10 1956 was a Monday.
Wednesday.
It was a Thursday.
From a perpetual US calendar: December 31, 1956 was on Monday.
December 12 can fall on any day of the week.
December 6th, 1956, was a Thursday.
December 14th, 1956 was a Friday.
December 16 1956 was a Sunday.
December 13 1956 was a Thursday.
December 28, 1956 was a Friday.
December 26th, 1956 was a Wednesday.
December 3, 1956 fell on a Monday.