Flowering time question

[2percentmilk]

So, wherever I look in grow journals everyone flowers at 12/12. What if I were say to start at 18/6 and over the course of a 2 month veg slowly reduce the amount of light I give them would it be possible for them to flower with more than 12 hours of light just how my outdoor crop will begin flower at 15 hours of light?

 

[2percentmilk]

Is no one else curious about this if it were possible wouldn't it be much more efficient and produce much bigger buds than the latter way