_Whose_ permission is needed? You're their parent , that's all the "permissions" needed.
The school is allowed to make an exemption for a maximum of 10 days, above that you need to contact the school attendance officer. This can only be provided if the reason falls under some specific types.
If you want to take your children on a holiday outside the national holidays, you have to provide proof that this only a possibility during term time.
You can read more about this at https://www.government.nl/topics/compulsory-school-attendanc...
So now you are not free to do whatever you wish or force schools to teach the way you would like to.
And this is great.
And I also pulled my kids from school once or twice to get a better price on skiing but I am ashamed of myself.