do you count it from start of pre flower or .after the end of the stretch ? when they really starts to flower . your thoughts ?
also has any one had an auto flower be ready on the time the breeder said or is it allways the actual time they put on the pkts the flowering time only because i never had one flower and be ready in time but i grow outside … just some thoughts please add your thioughts also
Photos are timed from when you make the switch, whereas autos are timed from when the pistils appear as it’s impossible to tell otherwise.
Windows are just estimates really, it all depends on the genetics and how they express themselves in that environment.
Happy growing 
Trchnically you count the weeks after flipping lights but really a Cannabis plant is still in veg the first 2 weeks as it transitions into flower.
This is when they “stretch” giving one last burst of foliage growth attempting to outgrow everything around it creating additional branching to set itself up for flower.
Week 3-4 is when the plants start shift their focus to bud growth.
That is not how the industry measures it though. For the purpose of grow logs with photos the flower stage begins when you switch to the 12hr flower cycle or whatever you might be using.
The reason your times may go longer is it’s based off something close to ideal conditions. Even the best growers don’t typically achieve that at home which is partly why they give a wide range. That’s ideal lighting, airflow, co2 levels, temp and humidity, it’s tested under lab like conditions.