All of the ones I have been involved with before took closer to 24 than 18 months. the exception being is that if there are a series of patents, that relate to one another, and the first takes ...say 24 months...if there is similarity between the other related patents....AND...if the PTO uses the same examiner for all of them, then the ensuing re-exams usually take a little less time.

Based on the re-exams for PTSC the expected re-exam finished date should be somewhere between the next 2-5 months IMO.