Saint Nicholas Day is celebrated in the Netherlands and also in Germany, France, Belgium, and Austria so on December 5 and sixth. This is what they do for Saint Nicholas Day.
Some things they do on Saint Nicholas day are at night they get ready and lay their shoes in front of the fire place or at the door then the next day they are filled with percents. They even have parades where people dress as "Black peter" and a man dresses as St Nicholas or called as Sinterklaas.
Why they celebrate is because it's their religion they celebrate the Christ and Sinterklaas for helping Sinterklaas to have the day they have and they can have a time to be with there family.
work cited
"St. Nicholas Center ::: Netherlands." St. Nicholas Center ::: Netherlands. N.p., n.d. Web. 09 Dec. 2016.