Denmark's New Year's Eve custom of breaking old plates at doors is commonly called plate smashing.
Participants traditionally throw or break unwanted crockery against the doors of friends, relatives, or neighbors. A pile of broken plates outside a home is interpreted as a sign that the household has many loyal friends willing to visit and take part in the custom. Modern versions may use disposable or otherwise unwanted items, and the practice is less universal than its popular descriptions suggest.
Danish New Year's celebrations also include champagne, fireworks, and the midnight broadcast of the monarch's New Year's speech. Jumping off a chair or sofa at midnight is another widely reported custom, symbolizing a leap into the new year.
Plate smashing should not be confused with ordinary littering or with traditions involving breaking glasses at weddings. It is a seasonal folk custom whose meaning is social: the debris represents visits and friendship, not bad luck.