Of course even this is a very individual thing and it depends whether you're liver is healthy in the first place and how much damage you have done to it. Generally a healthy liver regenerates quickly and is very resilient to outside "poisons." If you do a lot of heavy oral cycles and drink on top of that, it will take longer and longer for it to get better/normal.
My training partner did 40 mg dianabol for six weeks and then had doctors check up for work reasons after two weeks of ending the cycle. His liver values were on the high normal end. So if i had to give somekind of an estimate for how long, i'd say three weeks. Of course this is just an estimate. Though many say and i agree that for an healthy individual the dangers of oral AAS are very exaggerated.