Depends greatly on your genetics.
I use the presence of new white hairs as an indicator that the plant is packing in more calyxes. When the production of these white stigmas really slows to a crawl is generally when the plant is entering the ripening phase. This is when I start watching the trichomes of the plant. When the trichomes are almost all white and amber, with very very few clear ones is when I choose to harvest. This usually takes 10 to 14 days to complete.
Even on strains that are advertised as 8 week strains I generally go to 60 days before even considering chopping.
