By law, in the Netherlands, employees are allowed to reduce their work hours. Allegedly, unless there is a clear, critical business need for you to work the entire week, the company is not allowed to deny your request.

I would love to work fewer days per week, and use the extra time to focus more on my personal development & side projects. However, at my current level of discipline, I'd be fooling myself if I said I would use the time productively.

That said, the idea is still very tempting and I intend to do it in the next couple of years. In the meantime, I fully enjoy all of my 24 PTO days and make use of our policy for getting 5 extra unpaid days without justification.