The #1 single on the Billboard Hot 100 on 20 Dec 1985 was Say You, Say Me (Title Song from White Nights) by Lionel Richie.
"Top Of The World" - The Carpenters
enakedladies
Then-Brad Paisley
This Week in Country Music - 1985 1985-07-07 was released on: USA: 7 July 1985
The Billboard list was established on August 9th, 1958, so there was not a Top Billboard song of the week for the week of August 2. Records show that the number one song at this time was Poor Little Fool by Ricky Nelson.
December 13 1985 was on a Friday.
December 28, 1985 was a Saturday.
December 13 1985 was a Friday.
December 5, 1985 was a Thursday.
December 7th 1985 was a Saturday.
December 22, 1985 fell on a Sunday.
December 31, 1985 fell on a Tuesday.
December 26, 1985 fell on a Thursday.
December 27, 1985 fell on a Friday.
December 24th, 1985 fell on Tuesday.
December 19, 1985 was a Thursday.
December 12, 1985 fell on a Thursday.