Light Cycle

I'm in my 4th week of flowering and I want to change the light cycle hrs.the light is on from 6a-6p I want to change it to 10p-10a.I'm tryin to save energy with the light bein on when power usage is low.How can I change the power on time without shocking the ladies.Or should I wait it out til harvest time.

I would wait my friend, it will shock your ladies, not too bad but enough to regret it. Trust me Ive done it!