Because that's the time of Saint Nicholas. He comes by boat from Spain together with his black little helpers called 'Black Petes' who throw around typical candy for this year. Children sing songs and they get gifts on the 5th of December. There are al ot of traditions such as hiding a present in a self-made thing of interest of your friends or family. I really love the food of this year.
We also celebrate Christmas on the 25th and 26th, just without the gifts because we get them on the 5th already. Together with New Year's celebration this makes December a month full of holidays
