In Germany, most contracts (and any regular job has a contract) say something like 1 month notice for the first six months on both the employer and employee’s side, and 3 months for the employee after that trial period, and possibly longer for the employer after you’ve been around for several years.

My colleagues were shocked when I confirmed that offering more than two weeks’ notice in the US is super nice to your employer, and two weeks is not considered unprofessional.