In general, it takes about 6 to 8 weeks for the bones to unite. However, every case is unique, as no two fractures are exactly alike.
Now, this is only for bony union. This does not include the time it take the soft tissues to heal and be rehabilitated. It often takes patients as much as a year before they know their final result.
And, yes, use of nicotine (cigarettes, cigars, pipe, smokeless) significantly impeded fracture healing. Nicotine causes constriction of the small blood vessels. Fractures rely on the tiny blood vessels to form callus (the new bone that heals fractures), so nicotine really cuts down on the blood supply. It is recommended that patients try to quit, at least till the bone is healed and the soft tissues are well on their way.
It is known that nicotine use causes a significantly higher rate of delayed and non unions. In fact, some surgeons will not do elective orthopedic surgery on patients who cannot stop using nicotine. That is how significantly nicotine affects healing.
Surgeons understand that it is difficult to stop, but do try. It is for your own health.
Good luck. Hope everyone heals well and gets on with rehab soon.