National Remembrance Day honours the victims of World War II and subsequent armed conflicts. At 8pm, the entire country observes two minutes of silence — traffic stops, trams stop, people stand still wherever they are. The central ceremony takes place on Dam Square in Amsterdam, where the King and Queen lay wreaths on behalf of the nation. Local commemorations are held in nearly every municipality. If you are in the Netherlands on 4 May at 8pm, stop and stand still — it matters to the people around you.
Context you may want first: 4 en 5 mei, Tweede Wereldoorlog