really depends... plants are individuals. if you have good full spectrum light, solid intensity, proper timing, and it still seems slow...(rule of thumb IME is pre-flower lasts 3 weeks, then ~3 more weeks of bud building, then maturing into the swell into chop)... then messing with the photoperiod is the best way to speed this up but beware there are hormonal changes that come with this, or you can just skip the work and use hormones if comfy with botany principles