That's because that's when the kids don't have school. Here in the Netherlands, you can not take your kids out of school for vacation. It's against the law for kids to be out of school when it's in session unless they are sick, or they have permission from the school, which most schools won't grant an extended amount of time. There are very few things that are mandated that they have to give you time for....a parent's wedding, you get that day, but that's it. Funeral for an immediate family member is 1 or 2 days, I think? That's about it. Kids get 6 weeks of Summer vacation, starting some time in July and ending in August. It depends on the region, and it rotates. This year, my kids have the middle vacation, meaning they started vacation in the 2nd week of July and go back at the end of August. Last year they had late vacation, so they didn't get out until July 20th. Some people have kids in 2 different regions because you don't always have a school for your needs in your town. My daughter wanted to do Gymnasium, which is the highest level of school here, plus learning Greek and Latin, and she also wanted to do a dual immersion program. There are no schools in our town that offer both dual immersion and Gymnasium, so she'd have had to take a train to Arnhem every day, which is in a different region for vacation times. So she would have had different vacations from my son. My son has autism and goes to a special school for kids on the spectrum. Kids are bussed in from all over the area because it's the only school for Autistic kids in the area. If a kid comes from Didam, Didam's vacation is a week different from ours, so any kid from there would have a different vacation period from their siblings. So parents have to wait until August when ALL the kids have vacation at the same time. That's why August is the most common vacation month here.