The private schools are usually around 8 weeks. I checked into Kaplan before I went to a public supported vocational school (adult school) for my LVN and CNA. At the adult school I attended I had to take a semester pre-req course and then the semester CNA course. The CNA course was 5 days a week! This was in Santee in San Diego county. Both of those courses were the pre-reqs for my LVN school. I think those classes were great preparation for Vocational nursing.
I was really surprised to see a CNA training program at a LTC near me. I was just checking the websites of LTC's in my area and it was stated on the web page that they will give you free CNA training. Check around in your area and see if maybe you can find the same thing.