Shawn has it right, as usual. The flights take typically from 1 to 5 days, depending on how complex the equipment is (one hour for a dirt-simple vfr machine, 7 hours for a complex IFR bird).
A run through all the equipment, many in real situations - real navigation runs, instrument approaches, auto-hovers, etc. For complex military machines, a complete run-through the equipment might include a mine-sweeping exercize, for example.
Production pilots have to know the systems, and usually write the acceptance test procedures, they must be technically sharp, and are often engineers. It is a stepping stone to experimental and then research pilot for many manufacturers.