There are a lot of variables. For example, the harvest I started two days ago won't be done for two more days.
Do I go just right on the first day's trim or the last day's trim? Or average?
I went with last day, putting the hang date as saturday.
Four day minimum hang time and that is wednesday.
Thanksgiving weekend starts thrursday and everything is good to go.
The deciding factor is thanksgiving.
I grow a sativa with a two week window of opportunity. It does not develop amber trichomes. The hairs do get brown and start sucking back in on the bottom of the buds, but I harvest while white hairs are still on top, they don't seem to ever stop appearing.
I have gone as long as two weeks longer than recomended without damage to potency, just more difficult to harvest due to softened leaves. Adding that gives a month to play with.
THC appears slowly and disappears slowly. Taste, on the other hand, is much pickier.
On a new strain I will pick a bud every day or two and test smoke after a three day hang in a dry spot. This really helps for the next grow, I use the same strains year after year.
On my indica the window is a week, the hairs suck all the way back in and I call it good. Early and late smoke tests did not differ much, taste seems to be more in the cure with Northern Lights.