Sinterklaas (also called Sint Nicolaas, de Goedheiligman or simply de Sint in Dutch) is a traditional Winter holiday figure in the Netherlands and Belgium ; he is celebrated annually on Saint Nicholas' eve (5 December) or, in Belgium , on the morning of 6 December. The feast celebrates the name day (birthday) of Sinterklaas and is the basis of the mythical holiday figure of Santa Claus (Father Christmas).
Children leave their shoes out from Sinterklaas' arrival into the Netherlands from Spain on November 20th until the morning of December 5th. His Zwarte Piet's (literally black elves) leave "snopes" (candies) or small gifts every morning. Katie and Andrew have be lucky enough to receive something every day but one. Like Santa Claus, Sinterklaas sees when children are naughty or nice.
On December 5th, Sinterklaas leaves a burlap bag of larger gifts. Traditionally, this is the dutch Christmas morning. December 25th is the celebration of Jesus.