Wednesday
December 11th, 1980 was a Thursday.
31 December 1980 was a Wednesday.
27 December 1980 was a Saturday.
December 6, 1980 was a Saturday.
December 28, 1980 was a Sunday.
15 December 1980 was a Monday.
7 December 1980 was a Sunday.
December 26 1980 was a Friday.
December 20, 1980 was on a Saturday.
December 8th, 1980 fell on a Monday.
December 2, 1980 fell on a Tuesday.