German Unification Day

The Day of German Unity is the legal national holiday and celebrates the German reunification in 1990 as a public holiday. In Berlin, the day is celebrated with a festival around Brandenburg Gate.

On the 3rd of October 1990 the former GDR officially joined the Federal Republic of Germany. Since then the country is reunited.
It commemorates the anniversary of German reunification in 1990, when the goal of a unity of Germany that originated in the middle of the 19th century, was fulfilled. Therefore, the name addresses neither the re-union or union, but the unity of Germany. The Day of German Unity on 3 October has been a German national holiday since the reunification in 1990, when the German reunification was brought out in full force. 3 October is a legal holiday of the Federal Republic of Germany.
An alternative choice to commemorate the reunification could have been the day the Berlin Wall came down—9 November 1989.

Celebration
The historical event of German reunification is celebrated every year during a four-day-long folks festival.
German Unity Day is observed with speeches, marches, and public events, including the government's official Unity Day celebration street festival, which draws about 300,000 people annually.
Every year a different city plays host to the official Day of German Unity celebrations to mark the peaceful unification of the former East and West Germany in 1990.