People start throwing shredded paper out of the windows, and buckets of water to say goodbye to the old year. Traditionally the papers that are thrown are sheets of the old year's calendar, torn out the last working day.
It's fun, the space between buildings gets filled with calendar sheets with every day in the almost gone year dancing in an american beauty plastic bag kind of way. At the same time people rush out of the buildings to avoid unexpected showers of the randomly falling water, and the ocasional unlucky one gets soaked. It's an unusual and funny sight.