It's not really 30 days PTO, isn't it? It's "30 consecutive days", which might even include holidays/weekends. And you don't have much flexibility on taking them.
Also, it's not uncommon to have 40h agreements.
In Brazil you get paid monthly, not weekly, so weekends are part of the math. 30 weekdays would make it 42 consecutive days vacation - now that would be awesome.