Not really much to it…
What day do you consider the first day of flower?
A.) When you flip to 12/12?
B.) When pistils begin protruding from the node calyxes?
Or
C.) When pistils beging to protruding from actual flowering points?
Just curious to different opinions of it.
When I see pistils developing at the tips of the plant.
When i see the first pistols on autos
Usually when q tips form. Bout 10-14 days after the light flip for me.
When pistils appear, which is usually 1.5 weeks from switching light schedule.
You can flip your lights to 12/12 whenever you want after a photo period is sexually mature. Some do anywhere from 60-100day veg periods before they flip. And depending on how much height you have. I flipped this last girls at 45 days. This time I’m going for over a 75 day veg period before I flip. Alot consider flower the day you flip the lights. Some when pistills show. And some when buttons form on top. Lol another no REAL answer I believe
Because I grow mostly clones, I count both from flip and from first pistils. My thought that if I grow a clone and harvest it on day 60 from flip, then I should be able to plan on that. But for pics and the like, I use the from first pistils date.
Yep lol.
Only thing that’s important is final days of flowering.
Pistils on the tips for me
I count flower days from the day of flip.
C. pistils on the tips
Same here, when I flip the lights to 12/12 is when I start.
I can kinda get behind this line of thought…
edit: Of course, that really doesn’t settle the question at hand, but I count from 10-14 post-flip as flowering having started. The first week or two is the transition.
I used to count when I flipped, but most breeders say 8 or 9 weeks of flowering time, and I consistently go over by at least two weeks, so I think the right answer is to wait until you see pistils, then consider that the start of flowering.
i consider the first day of flowering is after a few pistils have started to develop and spread. But I don’t flip and I grow straight 12/12.
I’ve always counted from flip and added 10 days to the back end on the calendar . . . breeder says 60 days flower I figure 70 from flip to harvest. Normally gets me to within a day or three for harvest date. I don’t switch to flower nutes until I see pistils on the tops.
Those beautiful white hairs from the bud sites 
When I see those button buds appear. Usually about 2 weeks after the flip.
As soon as I see pistils, so B for me