It is entirely possible that it would evolve differently, perhaps given that not everyone would be available during the 'dark' hours you might see a society evolve into dual function, where 8 hours were for 'working' and 8 hours were for 'community/family' with 8 hours split into two 4 hour segments as 'transition times'.
I was thinking this as well. I suspect that it's impossible to predict, but I wouldn't think it unfathomable to imagine a world in which, with all the additional free time, society might evolve towards a more Italian ethos, in which we take longer lunches, and don't mind spending as much overall time 'at the office', though not necessarily working any more while there.
