Day Date Month Holiday
Sunday 01 Jan New Year's Day
Sunday 16 Apr Easter Day
Monday 17 Apr Easter Monday
Thursday 27 Apr King's Birthday
Thursday 25 May Ascension Day
Sunday 04 Jun Whit Sunday
Monday 05 Jun Whit Monday
Monday 25 Dec Christmas Day
Tuesday 26 Dec Second Day of Christmas
Source: https://www.timeanddate.com/holidays/netherlands/2017#!hol=9