Right now my plants are on 12/12 and have been flowering for 2.5 weeks, the light comes on at 6am and turns off at 6pm. For safety issues(apartment), I want to switch it so the light comes on at 6pm, and turns OFF at 6am. Will this screw up my plants?

Right now it's 5pm, so it's gonna go off in an hour and it won't come on again till 6pm tomorrow night(if i do the switch)which would be 18 hours of darkness.
tadaa Reviewed by tadaa on . changing lighting cycle on/off time Right now my plants are on 12/12 and have been flowering for 2.5 weeks, the light comes on at 6am and turns off at 6pm. For safety issues(apartment), I want to switch it so the light comes on at 6pm, and turns OFF at 6am. Will this screw up my plants? Right now it's 5pm, so it's gonna go off in an hour and it won't come on again till 6pm tomorrow night(if i do the switch)which would be 18 hours of darkness. Rating: 5