Klozum is a holiday feast celebrated every 5 December on the Dutch island of Schiermonnikoog. The name literally means "Uncle Claus". Despite the name and date, the tradition is not directly related to Sinterklaas, which is also celebrated on 5 December in the Netherlands. Rather, it is related to similar traditions on other Frisian Islands, such as Klaasohm on Borkum, Ouwe Sunderklaas on Texel, Opkleden on Vlieland, and Sunderklazen on Ameland.