On 12&12 you'll never know. Autos will flower regardless of the light exposure. Some autos can handle 24 hrs of light, most just stay on the "veg"(18&6) lighting schedule. Otherwise you are wasting the auto part. If you put an auto on a "flowering" light schedule(12&12) your buds will be fluffy and disappionting. This auto has had 18hrs of light every day of her life. The "auto" means that when she is ready she'll flower.