The distinction between past, present, and future is only a stubbornly persistent illusion.
--Albert Einstein
Sometimes I wake up late at night and wish I was there. A glowing hub of people wandering around enjoying the night, no special goal in sight. A place populated throughout all hours, with no sign of decrease. That is what really parts the big city and the metropolis: The possiblity to do whatever you want, whenever you want. My hometown has about 100,000 inhabitants, but due to strict employment laws and a lot of verrry conservative people nobody goes out too late on weekdays. In the hours between 2 am and 8 am, even on the weekend, the city is practically empty. All shops close at 7 pm and the pubs and bars at about 2am, so what shall the insomniac do with his time, exept from the net and TV-reruns?
I know the US is different, with shops and public places open in the wee hours, and I certainly have been to New York, where you at any time can be sure that there is someone shopping, crying, clipping toenails or climaxing in the near vicinity, but still nocturnal ventures are something a bit distrusted in most places in world.
I therefore advocate a future of consistant light as perhaps depictured in Nacy Kress's famous novel "Beggars in Spain", where a community of sleepless lives in an orbital station in neverending night, or even similar to Babylon 5, but in an earth bound, urban environment. Somewhere you can get to easily everytime you like to, frequented by people who you share values and interests with, without being bound to certain time window. To accomplish this, the life of a people would be bound not to a day, but to a shift, and since the labor of the future is not specifically in need of a 9 to 5 scheme you may change the shift, or sphere, you live in at will.
Many points of this very unspecific scenario may be ruled out exactly by the way society advances. Public services bound to special opening times may in future be done online, and 24/7 shifts would lead to full employment. The fear of a sci-fi author I have read, was that the time you live in could match social status, and people from 'different times' couldn't meet. That's why it must be self-chooseable and rather random to all people.
The only thing people then will fear is sleep.