Well, let’s put it this way: we can do an entire private or instrument in just a couple weeks of full-time training, so it’s not going to be longer than that. If you have most of the requirements met, we may be able to get this done over a long weekend or two.
It varies tremendously; finish-up programs can range from “I started my private training with 10 hours 30 years ago” to “I’m signed off for my checkride and my airplane is down for annual.” Any finish-up program is going to have two components: satisfying the FAA’s requirements, and flying to proficiency. The first is easy – we review your logbook and do the math. The second is more challenging and normally requires some time with one of our CFIs to determine. Once they’ve gotten a good idea of your flying skills, we can put a program together.