76 from seed .... Chop off 30-40 days of that ( seed / veg / preflower ) ...
That leaves you flowering for about 46 days at the most of ACTUAL flowering.
( close to week 7 ) ... Run her longer at least 2 weeks .
Breeder estimates are bullshit ... They are under OPTIMAL CONDITIONS to get that time frame described. ( controlled lab type grows ) .
For the rest of us ... Each will take as long as it takes. Autos are unpredictable , ( sizes , structure , feeding , health ). I ignore the breeder hype - once it transitions to flowering
THEN is where i begin " counting " weeks in flowering. You are in the swelling stage , pistil growth is still happening , monitor ONLY the triches ( forget the amber bullshit ) , look for trichcomes that are full and opaque . Plus you are in the beginning of leaf fade which is another sign that it is getting closer.
Autos MAY or MAY NOT turn amber ( certain strains ) , especially when you get to dominate crosses it may go either way. Stick with the usual maturing timing you would do with regular photos .... Patience will pay off.