Read and learn about history.  Pick out a good one.

https://en.wikipedia.org/wiki/December_3

1989 – Cold War: In a meeting off the coast of Malta, U.S. President George H. W. Bush and Soviet leader Mikhail Gorbachev release statements indicating that the Cold War between NATO and the Soviet Union may be coming to an end.

1994 – The PlayStation developed and marketed by Sony Computer Entertainment was released in Japan