I remember the wall coming done, something I never thought I'd see in my lifetime. I never realized that there was a German Unity Day celebrating that day. Have a fun and safe trip.
Just to be clear, Oct. 3 is to celebrate unification, but it's pretty much a random day. The wall came down some time in November and also the following year Oct. 3 nothing highly important happened.
We used to have a German Unity Day on June 17; which was the day there had been demonstrations in East Berlin and the Russians cleared the up with tanks... That "holiday" was cancelled and replaced by Oct. 3.
I am in Taiwan, so I'll be working on Oct. 3. (In exchange I just had Sept. 25 off and Oct. 10 will be another one...)