Manipulating light cycle to increase yields

So I discovered this technique trying to find strains that would finish by September in central B.C. where it can snow on September first so what I would do is start them on 24hr an reduce light daily like it does in nature to see when a plant will trigger in to flowering so after that I tried running 12 off 13 on or 14 on And also tried 14 off 14 on depending on the strain but after doing the light reducing experiment I was familiar with the strains I was working with and knew there magic number to induce flowering some trigger at 16 hours light 8 hours dark down to 12/12 so with the strains that required 12/12 I tried another experiment and ran than 14/14 and was surprised to see what a difference in yield that extra two hours of light made anyone else ever play around with this