Can I change my 12/12 times?

I have my grow tent in a dark room.... The room allows some light in through where the room vents at. I have my 12/12 going from 11pm to 11am.

Based on sun times and the amount of light that can enter that room, can I switch my times to 8pm to 8 am without harming the schedule I am on now? If show should I set it back to have a shorter light time before the new time set or a shorter dark time before the switch?

As always, help is appreciated.

Best,

Anyone? Will the time changes hurt?

it will be fine if you do a shorter light period to get things at the 8am-8pm. its only a 3 hour diff for one day not a big deal