What day of the week was December 31, 1999?

The day of the week December 31st, 1999 fell on was a Friday.

Elliot Richardson the American lawyer and politician, 69th United States Attorney General (b. 1920) died on this day in 1999.

First President of Russia the Boris Yeltsin, resigns from office, leaving Prime Minister Vladimir Putin as the acting President and successor. The United States Government hands control of the Panama Canal (as well all the adjacent land to the canal known as the Panama Canal Zone) to Panama. This act complied with the signing of the 1977 Torrijos–Carter Treaties.