Historical timeline for December 31

The World Health Organization issues its first emergency use validation for a COVID-19 vaccine.

The World Health Organization is informed of cases of pneumonia with an unknown cause, detected in Wuhan. This later turned out to be COVID-19, the cause of the COVID-19 pandemic.

Thirty-nine people are killed after a ten-story building collapses in the industrial city of Magnitogorsk, Russia.

A fire breaks out at the Downtown Address Hotel in Downtown Dubai, United Arab Emirates, located near the Burj Khalifa, two hours before the fireworks display is due to commence. Sixteen injuries were reported; one had a heart attack, another suffered a major injury, and fourteen others with minor injuries.

A New Year's Eve celebration stampede in Shanghai kills at least 36 people and injures 49 others.

NASA succeeds in putting the first of two Gravity Recovery and Interior Laboratory satellites in orbit around the Moon.

Tornadoes touch down in midwestern and southern United States, including Washington County, Arkansas; Greater St. Louis, Sunset Hills, Missouri, Illinois, and Oklahoma, with a few tornadoes in the early hours. A total of 36 tornadoes touched down, resulting in the deaths of nine people and $113 million in damages.

Both a blue moon and a lunar eclipse occur.

The official opening of Taipei 101, the tallest skyscraper at that time in the world, standing at a height of 509 metres (1,670 ft).

Rwanda adopts a new national flag and anthem.

Indian Airlines Flight 814 hijacking ends after seven days with the release of 190 survivors at Kandahar Airport, Afghanistan.

The first President of Russia, Boris Yeltsin, resigns from office, leaving Prime Minister Vladimir Putin as the acting President and successor.

The U.S. 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.

The European Exchange Rate Mechanism freezes the values of the legacy currencies in the Eurozone, and establishes the value of the euro currency.

The final comic of Calvin and Hobbes is published.

The First Chechen War: The Russian Ground Forces begin a New Year's storming of Grozny.

This date is skipped altogether in Kiribati as the Phoenix Islands and Line Islands change time zones from UTC−11:00 to UTC+13:00 and UTC−10:00 to UTC+14:00, respectively.

Czechoslovakia is peacefully dissolved in what is dubbed by media as the Velvet Divorce, resulting in the creation of the Czech Republic and the Slovak Republic.

All official Soviet Union institutions have ceased operations by this date, five days after the Soviet Union is officially dissolved.

Three disgruntled employees set fire to the Dupont Plaza Hotel in San Juan, Puerto Rico, killing more than 90 people and injuring 140 others, making it the second-deadliest hotel fire in American history.