My brother is a professional firefighter here in Germany (we also have volunteer firefighters) and he has two 24 hour shifts per week and usually 48 hours between them but that obviously isn't set in stone (sick coworkers...). He should at least get 12 hours off by law , I think. His shifts also rotate a bit. Like it's not always monday at work , tuesday and wednesday off. After a bit he'll move to tuesday at work and wednesday and thursday off and so on . With holidays it's usually parents who get the Christmas holiday but you can't have both, Christmas and New Year's Eve unless you find someone who's willing to trade shifts.