It doesn't matter what time of day you run your lights, except for your convenience.. Some ppl prefer day-time light access, and others prefer to run the lights through the night so the operation is stealthier during day-time..
If I had to alternate scedules instantaneously, I'd opt to increase the daylight hours until switch time, rather than shorten daylight, or mess with the dark cycle..
eg. If you wanted to run lights the exact opposite hours tomorrow, I'd give them light for 24 hrs until your desired dark time.. Or if you want lights on 6 hours later, give them 18 hours of light.. If you want them on 6 hours earlier, thats 30 hrs of light until desired shutdown..
This opinion is mainly the result of alot of convoluted reading.. Personally I've never had to tinker with that, but a friend did, and he had very little problem using that method 3 freakin times..
Obviously though, if you can stagger it you're better off..