Question abt switching to 12/12

I have a nice little crop (19 plants) that I have been vegging in my basement 24/24 under full spectrum flourescents for almost 2 mos; 2 separate germinations about 2 weeks apart of Aurora Indica, Bubblegum and Super Ice. The tallest are almost a foot, and the shortest are significantly shorter but have low clusters of leaves (somewhat bushy) as a result of the lighting. In switching them to a timer, is there any advantage or disadvantage to using less than 12/12? I'm not so sure about the accuracy of the timer and currently have it set for less than 12 hrs of light; will this stress the plants and make them go awry for some reason...?

I need to transfer them to the outside because the house needs to be vacated and I was hoping to sex them before the transplant. I'm planning on moving them to a second floor of our garage to become aclimated to the environment before strategically planting them throughout the yard. I've checked the charts and we don't expect days of 12/12 until mid Sept. to early October. I'd rather have them sexed before committing to having to find so many hiding spots and then having to thin them out later in the year.

Any advice would be appreciated! Thanks~!

Some strains will flower with more than 12 hrs of light. Say 13 or 14 hrs. They say with more light you will get better results. I just leave mine at 12/12. I havent tried to experiment but that should answer your question. You will need to bud for about 10 days to tell sex.