Store bededag / All prayers day
The right thing to do the evening before All payers Day, (beside eat warm bread) would be to take a walk aroud the old Citadel in Copenhagen, and by that keep an old Danish tradition alive.
The citadel is about 350 years old, it is one of the best preserved star fortresses in Northern Europe (Wikipedia).
Blogpost 2013 about the tradition
History (In Danish)