Denmark is traditionally associated with breaking old plates outside friends’ homes on New Year’s Eve.
The custom involves saving unwanted crockery and smashing it against the doors of friends or neighbors around New Year. A large pile of broken dishes was traditionally interpreted as evidence that a household had many friends and well-wishers. The practice is often described as a symbolic way to leave old, unused objects behind while welcoming the new year.
The tradition is much less universal than Denmark’s other New Year customs, and modern participation varies widely. It should not be presented as something every Danish household does. Contemporary celebrations may instead focus on fireworks, festive meals, speeches, and the midnight song “Vær velkommen, Herrens år.”
Denmark also has a distinctive midnight dessert tradition involving kransekage, a ring-shaped almond cake often built into a tower. Breaking plates is therefore one memorable Danish custom among several, not the defining feature of Danish New Year. Similar object-breaking customs have been reported elsewhere, so the question refers to the tradition most commonly associated with Denmark.