Speaking for Germany: in former times, a "Habilitation" war required for a fukkfull professorship - which you usually wrote during your post-doc phase. It usually took about 6 years (of course with strong variations). Now, you can qualify for a full professorship by beeingbeing a "Junior Professor" - which takes 6 years with in interimsan interim evaluation after three years. In some cases, junior-professurshipsprofessorships can be transformed to full professorships after six years, but if this really happendshappens depends strongly on your univrsityuniversity and faculty (in fact politcspolitics says it should be the norm, but in fact universities are having much more junior professorships than full professorships).
So the general norm in Germany is 6years+, since you usually won't get a position right after your PhD.