Understandable, just like in the EU each country has their own rules concerning vacation days and PTO, but they're likely closer to the Dutch rules than the "general" US rules if what I've been reading on Lemmy and Reddit.

It gets paid out at the end of the year.

Luckily this is protected, since paying out days off is taxed at 52% in the Netherlands, so you'd lose half the income for not going on holiday.