When to start counting the beginning of harvest?

Hello RIU I have a simple, maybe even dumb question that I hoped to get help with here. I have 5 plants that have been flowering for about 8 weeks now, but I am unsure of when to count them as starting to flower? What I mean is, do you start counting the first week of flowering right when you switch to 12/12 or do you start counting down at the first sight of flowering pistils? These girls are outdoor so I did not switch to 12/12 they started to flower on their own. Any help appreciated very much thank you!

The very start of 12/12,not when the first hairs show. I had wondered the same thing and saw my question answered.

I'm opposite. I start the count at the 1st sight of pistils.

Never..plants have their own clocks. They like to fuck with ya. I start my clock at seeing flowers truth be told..

i dont count days anymore. its pretty useless IMO, and just makes things seem like its taking forever (not that it doesnt already )

better off looking for the plant to ripen, and check trichs.

Ok thank you guys I appreciate all the info! I know that I should check trichomes with mag glass which I was doing until my mag went missing! Cant find it, I ordered one online but from china so it will be at least another week and the outdoor girls have been flowering for about 8 weeks. I have two that are turning purple at the flowers and leaves but not all the leafs yet just some.