forced flowering ?

I'm growing outside.

Once you force a plant into flowering do you have to maintain the 12/12 cycle until harvest?

Last year i let mother nature do her thing without any artificial help to start the flowering process but ended up having to protect my plant from frost. So this year i'm thinking of starting the flowering early by forcing it (to help pull in harvest time) but don't know if i need to maintain the 12/12 or not.

Any useful suggestions would be appreciated. Thanks.

Yes, it has to be on a strict 12/12 light cycle, if not it could hermi..