It can vary, but for me it was 6 weeks of immobilization (watercast), 6 weeks of range of motion type stuff, and then another 12 weeks of strength with mainly isometrics before I was cleared to surf. PT was typically 3 times a week but you're still doing PT every day. Even after 6 months though it wasn't for until a full year that I really felt comfortable with the shoulder. Those first times out I'd dial it back when paddling for fear of re-dislocations...Continuing PT exercises and taking up weight training I think were key as everything has stayed in place for the past 6 years.
Whoa. 6 weeks in a sling / watercast. Depressing just thinking about that aspect.