Warning

School holidays for the International School Hilversum and the IPS Hilversum often differ. Parents with children in both schools should check the school holidays before booking. And to add to the confusion both schools may differ from the standard school holidays in the Netherlands which are determined by regions.

The regions are:
North: Friesland, Groningen, Drenthe, Overijssel, Flevoland, Noord-Holland, Municipality Eemnes (Utrecht)
Middle: Gelderland (some municipalities), Utrecht (except Eemnes), Zuid-Holland
South: Gelderland (some municipalities), Zeeland, Noord-Brabant, Limburg

For the dates of the Netherlands school holidays, see: 
⫘  www.rijksoverheid.nl/onderwerpen/schoolvakanties