From Middle Dutch saterdach, from Old Dutch [Term?], from Proto-West Germanic *Sāturnas dag, calque of Latin dies Saturni. Compare Low German Saterdag, West Frisian saterdei, English Saturday.
Saturn or Saturnus is the sixth planet of the solar system, and it was the name ot the Roman god of fertility and agriculture.
zaterdag m (plural zaterdagen, diminutive zaterdagje n)