How long a #rhinoplasty takes depends on several factors.
The skill and knowledge of your surgeon. (The exception to this is Dr. Dean Toriumi who is actually a great surgeon but takes routinely 6-8 hours for a rhinoplasty due to teaching other surgeons, performing studies on each nose and placing numerous grafts). Usually though more indecisive or inexperienced surgeons will take longer.
The type of surgery your surgeon is going to do. Open rhinoplasty and revision rhinoplasty usually can take longer.
What is needed for YOUR particular nose. Some nosejobs can be done in minutes and some take hours.
If a resident or fellow in training is doing your surgery it will take longer. Make sure you know 100% WHO is doing your surgery. If you go to a teaching hospital like Johns Hopkins, there is a good chance a resident is doing a good part of your surgery.