Hey there GREAT Question?
This is something no one ever talks about and when anyone tries to bring it up everyone chips in and is like that’s bro science.
I have actually experimented with this a lot.
When you think about it in nature weed plants get harvested at the end of summer begging of fall. So in nature the amount of light will peak a few weeks b4 harvest.
I have experimented with lowering the light intensity at different times I have concluded that it doesn’t matter if it’s harvest time or not if you lower the light intensity like 15% to 25% for 2 weeks the plant will start to finish up even if it would if normally went longer
My take away is that you can force plants to be ready for harvest early by doing this you would possibly cut about 10 days off of harvest by turning down light intensity early
Now with lots of experimental with the topic I think it’s good for the average plant that is supposed to go between 8 to 10 weeks I would slowly increase light intensity until the end of week 7 then over the next 2 weeks slowly lower light intensity around 15% gradually
What this does when done at the correct time in my experience is the hairs seems to change colors all at the same time instead of top to bottom of the plant also the buds seems swell up more when I do this
Good luck