When does flowering schedule begin?

I've heard this both ways, so I wanted to get an opinion... When you go to 12/12 for flower does that mean flowering starts that day or does it start 1 week later? Basically, which week should you start using the flower week #1 schedule?

Also, I have an analogue timer... Does it make sense to do 11 hours 45 minues light and 12 hours and 15 minutes dark to make sure they get the full 12 hours of dark? I just don't know if I trust the timer? Does it matter if it's a few minutes off or will that screw something up?

Thanks!

there is no opinion. scientifically speaking it's flowering the instant dark periods reach the threshold governed by genetics, on the first night. on a mature plant..

No that's not necessary and they will flower with a little over 12hours even if pure equatorial sativas or whatever

start counting from the day you switch to 12/12
however the time stated is just a guide not a guarantee
your own growing conditions and phenotype differences
are also factors that will contribute

the timer is ok 15 mins will not make a difference

peace

pretty positive that the second bouncy is still my favorite.^^^^^^

JoeD1rt said:

pretty positive that the second bouncy is still my favorite.^^^^^^

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Can.. not... get... them.. ouuu...ttt... of... my mind

Merry xmas mate