I always thought it was six months, however I am proven wrong. I ended up doing my fitness test back in October and did quite well. Six months pass and I just did it a second time because my first one expired. I think it‘s a bit ironic. Don‘t worry about the PT test, just do your best, I went in there with my palms so sweaty that the meter fell out of my hand during the grip test, but I passed and felt really positive. If you fail it, work on what you did well, and work harder on what you did poorly on. That‘s my advice to you, enrollee to enrollee. Good luck.