This little wonder was indeed shot in Amsterdam. The post office folks are not obliged to speak English, but lo and behold, they felt compelled to express themselves in some sort of English. This was literally translated from Dutch. If you see nothing wrong with the syntax (the sentence structure), then you either do not know better or have been Dutchified.
I personally enjoy the ‘who are open’ because in French, it would be ‘who’ (‘qui’ sont ouverts). Since this is not Brussels where things are supposed to be bilingual in theory but are not in practice, my comparison is not very useful. Fact is, people throw a few English words together and actually think it’s OK. That’s what worries me.