The German Unity Day takes place on October 03, 2017. It is a day to celebrate the anniversary of German reunification in 1990. The day is celebrated annually. The Day is also the anniversary for the re-founding of the five states Brandenburg, Mecklenburg-Vorpommern, Saxony, Saxony-Anhalt and Thuringen. Unlike most other countries, flags on private houses, military parades and fireworks are not common on this day in Germany.
The Day of German Unity is celebrated each year with a ceremonial act and a citizens' festival ("Bürgerfest"). The celebrations are hosted habitually in the state capital of the German state presiding over the Bundesrat in the respective year. (With material from: Wikipedia).