not really a set time .. a couple of signs .. roots pokeing out the drain holes of your pot ... or ... your plant will start to grow slower and show signs of stress ..
1. seeds/clones start in pellet or rw cube
2. rooted plants/clones go to a 16oz dixie cup for 2 weeks
3. plants go to 5gal buckets for the remainder of the cycle
just try not to transplant too much i dont transplant more then 2 times!
if your plant is already growing at a weird angle like that you should just lst it for even better results after it has enough growth but in the meantime just let it do its thing