After the fall of the Berlin Wall, the national holiday was moved in 1990.

Until reunification in 1990, the “Day of German Unity” was June 17, date of the suppression of the 1953 popular uprising in the GDR with the help of Soviet tanks.
Why now October 3, a soulless administrative act?
I would have another suggestion…
My choice would be November 9. It would be the perfect synthesis: Reichskristallnacht (Night of Broken Glass, a pogrom against jews by Nazi Party’s paramilitary forces SS and SA) and the fall of the Wall both fell on this date. What could better illustrate the positive development of a nation?
Of course, I am aware that this proposal will meet with rejection. Who wants to “celebrate” German unity on the anniversary of the Reichskristallnacht? Neither do I. I would “commemorate” it on this national holiday – including the light and dark sides. That is history.