1 January - New Year's Day
Easter Monday- date is different every year
27 April - King's Day
Ascension Day Hemelvaart- date is different every year
Whit Monday 2e Pinksterdag- date is different every year
25 December - Christmas Day
26 December - 2nd Christmas Day
The Dutch government has divided the Netherlands into regions: North, Central and South . The aim is staggering the school holidays across the three regions is to control peaks in holiday traffic.
More information on school holidays is available on https://www.government.nl/topics/school-holidays/question-and-answer/into-which-regions-is-the-netherlands-devided-for-the-school-holidays.
Please keep in mind that international schools often have different holidays than Dutch schools and each international school has its own holiday calendar.