If you're at a level 12, not even close. Generally speaking nobody new is checking out in anything higher than a level 9 in 13 months. Some ARTCCs (centers) are backed up big time. Expect 5 years. Some aren't as backed up, 2-3 years would be more common. Terminal, long story but at a level 12 TRACON, don't expect to make CPC/FPL ever off the street. The biggest factor for how long it takes is how many people do they have to train you vs people needing to be trained. If they have 50 people that can train new people, and 150 new hires, you do the math. Its a different story than if say there are 30 people who can train new people and 3 new people need the training. If you hit a backlog, you will not train. You will wait. That will drag out the process. That said you could easily go to a lower level facility and get done in 6 months
The thirteen months refered to in the hiring announcement is the probation period. Many jobs have that. Basically you can get figred without the FAA having to provide any reason in your first 13 months.
Honestly the best answer anyone can give you is between 6 months and 5 years. So many places vary by so many factors. Its like asking what is the payroll on an MLB team, heck I could field one for 10 million, but how much are the Yankees on the books for 300 million? Just get a little more involved in the process and find out what kind of ATC and where in the country is more to your liking and then re ask the question might be the best for a better answer.