Hey there , timing your plant like that isnt really the best idea because different breeders do things differently so one breeder and the next will have differences in how they say their flower time. plus you dont really know the conditions that the breeder had, maybe they're doing it indoors with hydro and using all sorts of techniques you're not, so that will obviously affect the growth rate. The only real way to figure out when you've got to harvest is to look at the trichomes using a magnifier, anything over 40x and you should be able to see them, then make a choice on how you want your weed to be that means how much amber you want in there. but yeah, usually i've found a fair few weeks over the breeder recommendation usually works out. Hope this helps ! 🚀