I wait for all the pistils to turn brown and recede back into the calyx (with the calyx swelling up. On that plant, it would probably be at least 4 weeks if not 6 or so. My last auto grow went 14 weeks total.
@JE2100 about 4 weeks mate but the best way to ascertain whether your buds are mature is to use
a Loupe to check the trichomes
they should have turned from clear to clouded and preferably 10-20% of them have progressed to an amber color
this will provide the High quality you are expecting 👊