It's not entirely uncommon, even companies like Volkswagen have 3 weeks of summer vacation. Strictly speaking, some people still work there for maintenance, etc. that can't be done while making cars, but the majority is on vacation.
I know a handful of companies with a week of mandatory Christmas vacation as well (but there's typically not too many working days between Christmas and New Years' either way).
I know a handful of companies with a week of mandatory Christmas vacation as well (but there's typically not too many working days between Christmas and New Years' either way).