The way the law works here is you get five weeks vacation every year and have a right (but not an obligation) to take four of those consecutive between June and August. You must however take four weeks of vacation every year, the rest you can save for up to five years (before you have to take them as well).

Oh, and to really blow your mind, if you get sick during vacation, those count as sick days and you get the vacation back.

Although personally I’d rather work through August just to avoid millions of families with kids everywhere. Holidays are so expensive at that time of year.

Here in Denmark

in most places at least, you can choose the times you want vacation. Some places to "force" their employees to take 3 weeks during june - august... but then you still got 3 other weeks you can sprinkle around the year. (a lot of other places dont care)

and yes, i know a lot of people who spend their main vacations in may, or september. My mother mostly travels in the off-months (hotels, plane tickets etc, are also cheaper)