Changing lights on time question

I just switched to 12/12 2 days ago and set my lights to go on from 8pm to 8am.
I would like to change it from that to 6pm to 6am. Can I do this without stressing my plants and if so, then what would be the best way to do it? Thanks

Ya, just switch them.. do it soon.. no worries.

well.. the plant needs 12 hrs dark ATLEAST. so just start ur lights at 8p and turn em off at 6 am . them turm em.on at 6 pm.. jmo