Flower phase

Those first few white hairs I call pre flower, and once its really obvious she is in flower1-2 weeks after that depending on the strain, I call it flowering after that. But ive never been one to count days, and only the last few years have even bothered counting weeks. The plants are ready when they are ready my friend. If its a photo then you switch it when its big enough, and harvest it when its ready. If its an Auto then you just harvest when its ready. If thats 60 days or 72 days or 97 or even 112 days- thats what it takes. No one knows when it will be ready except for the plant. The rest is minor details like what nutes to give when- and thats pretty easy-if your not sure if shes in flower stick with veg nutes. When your sure switch to bloom/flower nutes. It really doesnt matter if your a week out either side- the plant wont mind. As long as it gets some nutes its happy during pre flower and the first few weeks of flower- yes more potassium is better but its not like veg nutes dont have any P or K in them either. And smaller buds dont need loads of P or K just yet- more than before but not heaps yet either ok. So counting days is more for the grower than the plant. When your sure its in flower switch nutes, til then dont stress ok. it will be fine.

You should start counting your flowering days from the day you see the first pistils emerge on your plants.

It is not important. It is just a number and plants don't know how to read or do math. I think of my plant in more than just two phases; seed, sprout, veg, pre-flower, flower and harvest. I count flower when I have the first actual buds, with pre-flower beginning a couple weeks before.

Technically it's when you see budlets. The pistols you first see is pre-flower which usually lasts 2-3 weeks.